Every year, thousands of women are trafficked to New York City from Latin America, and lately China, to work in brothels and massage parlors or as out-call prostitutes.

Statistics are hard to come by because the trade is hidden and victims rarely come forward — blocked by language barriers, leery of law enforcement and fearful of vengeful pimps who threaten to kill their families.

Last month, eight members of a gang of pimps pleaded guilty in Brooklyn federal court to racketeering, sex trafficking of minors and human smuggling. Each member of the Rendon-Reyes gang — a family enterprise that terrorized and trafficked girls and women for a decade — faces life in prison.

The Anti-Trafficking Initiative at Sanctuary for Families interviewed 356 suspected victims of sex trafficking in Queens and Brooklyn last year, according to Lori Cohen, a crusading lawyer and the initiative’s director. The previous year, it interviewed 245.

Sandra, 30, is one former sex slave helped by Sanctuary for Families. Kidnapped from her hardscrabble hometown in central Mexico and forced into the sex trade at age 19, she escaped her pimp-captor in 2011 and has received counseling, legal aid and health care from the group ever since. Wanting to protect her family, Sandra declined to provide her last name.

Here she tells her story:

On a good day, I’d only have to sleep with 30 men.

I always wore a tight, short skirt and stilettos. Alfredo was my “padrote” (pimp), and he arranged for different drivers to take me through Corona, Jackson Heights and sometimes Brooklyn. I would nod off in the car. I had a different driver every week.

On a bad day, when we left New York and went to Long Island or Connecticut, I couldn’t rest. One day, over the span of 16 consecutive hours in Boston, there were 80 men.

Alfredo beat me, refused to give me food or even water. The drivers he worked with advertised women on a “chica card” that they handed out to potential clients as they stumbled out of cheap nightclubs in Queens and Brooklyn.

I was also forced to hand out the cards to potential customers. Sometimes the cards had pictures of nude women. Other times they advertised children’s birthday parties. Everyone knew what the cards really meant; that the number on the back was to arrange deliveries of women.

We were delivered like pizzas.

Some of the men were day laborers. But some were well dressed, in suits. If they spoke Spanish, they paid $35 for 15 minutes, but if they spoke in English, the price went up to $45. For that price, the men could do whatever they wanted with me.

People think that prostitutes somehow enjoy what they do, but I can tell you that’s not true.

I had never been a prostitute. I did nothing wrong, but I was raped every day for the four years that I was a prisoner.

I was not part of the Rendon-Reyes group, but my captors used the same kind of tactics, I’m sure.

Alfredo beat me up, and he threatened to kill my family if I didn’t do what he said.

I was born on a farm on the outskirts of a small town of barely 3,000, surrounded by mountains.

There is a lot of hunger and poverty where I come from. I have 16 brothers and sisters, and sometimes I would come home from school and there would be nothing to eat.

I only completed the sixth grade, and then I stayed home to help my mother. When I was 16, I began working six days a week in a shoe factory where I made about $4 for 11 hours of work.

I met Alfredo by chance when I was 19. I was doing errands for my mother in the center of town when he approached me. He was also 19, and he said his older brother was looking for help in his cellphone store. I gave him my home number, and a few days later, he called me and offered me the job.

After working for a week, Alfredo told me he liked me a lot. He said he wanted me to meet his parents and asked me to go with him to another town, which he said was 30 minutes away by bus.

I met him at the bus station, and while I went to the bathroom, he bought the bus tickets.

We got on the bus, but after an hour passed and we still hadn’t arrived I started to get nervous. And then another hour passed, and it started to get dark. I panicked. You have to understand that I had never left my little town in my whole life. I kept asking him where we were going, and he insisted he was taking me to see his parents.

I hadn’t told my mother about Alfredo, and when he forced me to call her on his cellphone and tell her not to worry about me, I knew immediately what she would say.

I told her I was with the man she had only seen from a distance in town, and she called me a “pendeja” (idiot), which was really nasty, and she hung up the phone.

After more than four hours, we arrived in Mexico City. At the bus station, we took another bus for two hours and then a taxi to Tenancingo. I didn’t know it at the time, but Tenancingo is the world capital of sex trafficking.

It’s where the Rendon-Reyes gang had its base. All of the houses are newly built and everyone seems to drive new cars. They have an Easter parade where the pimps march down the main street showing off their prostitutes.

He gave me a sponge soaked in alcohol and told me to insert it. I couldn’t remove it during the long days that I was repeatedly raped.

We arrived at dawn, and I remember that Alfredo called someone on his cell and said, “I’m here with the girl.”

I was tired and hungry. I had only had a bottle of water and the cookies they gave us on the bus. Alfredo’s sister opened the door of one of the big houses in the town and showed me to a small room upstairs. She handed me some skirts that were too big, and a thin packet of pills. She told me that they were for birth control. I didn’t understand why she was giving them to me.

Later, Alfredo came to my room. He ripped off my jeans and raped me. It was my first time. I couldn’t stop crying.

I was locked up in the house for days, without food and water. When I saw Alfredo again, he said we were going back to Mexico City to visit another sister.

On the first day at his sister’s apartment, she handed me a pile of sheer pants, short skirts and high heels. I had no idea what a prostitute was. They told me that I would have to pay for my food and rent, and that I would have to work as a “puta” (prostitute). I told them there was absolutely no way I was going to do that. They told me that Alfredo would beat me if I didn’t.

One day, we went to La Merced, the red-light district, and I was taken to the street of the whores. They put me on a corner where there were other girls with short skirts and a lot of makeup. They told me I had to charge 150 pesos (about $8) for 15 minutes. I was told that I could only lift my skirt for that amount. If men wanted something else, they would have to pay more. Out of that money, the hotel managers would take 45 pesos. I had to clear 1,500 pesos per day.

The men who saw me knew I was new and began to chant, “Carne fresca” (fresh meat).

I started off with only five men and tried to tell the others who approached me that I was unavailable. But as the days passed, I eventually got up to 30 men per day.

Alfredo didn’t want to lose any money when I was menstruating, so he gave me a sponge soaked in alcohol and told me to insert it. I couldn’t remove it during the long days that I was repeatedly raped. I was in a lot of pain.

After three years in Mexico City, Alfredo said we were going to New York. He promised not to put me on the street anymore, that he would find me a job cleaning houses. His sister, who lived in Corona, would help, he said.

I didn’t believe him, but I went along with him because I heard that I could get help in America. I also had a sister living near Washington.

It took us two tries to cross the border. Alfredo paid a “coyote” $3,500 per person to get us across in a series of vans. The first time, we were traveling with his sister-in-law, and we were caught by border patrol.

When they plugged the sister-in-law’s information into their computer, they knew immediately that she had worked as a prostitute. They asked if she was coming back to teach me to work the streets.

The sister-in-law pinched me under the table, a warning to keep my mouth shut. I was so frightened that I couldn’t speak.

The men who saw me knew I was new and began to chant, “Carne fresca” (fresh meat)

We made it across the border on our second try, crossing in Texas. The coyotes left us stranded for days in Laredo until we could arrange for a van to take us to New York.

We arrived in Queens in February 2010.

I was forced to live at his sister’s apartment. His sister was a madam and a prostitute herself, and she arranged the “deliveries.” When I went to visit my own sister out of state, Alfredo wouldn’t leave my side. I was afraid to tell her what I was going through because I was still under Alfredo’s control and afraid he would send someone to kill my mother, whom I had spoken to only a few times since leaving my village.

In New York, Alfredo began to trust me and gave me my own cellphone, mostly to keep track of my appointments. But he still beat me. Once when I was speaking to my mother on the phone, and I tried to tell her the truth, he yanked the phone out of my hand and kicked me in the stomach so badly that I started to hemorrhage. His sister gave me a glass of beer mixed with a teaspoon of sugar and forced me to insert the sponge. I was doubled over, and my insides were on fire, but I had to get to work.

Alfredo used the money I brought in to build a house in Mexico and buy a car for his father. He also bought himself expensive clothes and gold chains. He gave me a tiny gold medallion of the Virgin of Guadeloupe, which I wore around my neck.

One day, a year after arriving in New York, I called my sister and told her everything. She said she would help me.

It was after the trip to Boston and the 80 men that I decided to make my getaway. During that trip, one of the customers tried to rob the brothel and pulled a gun on me. He let me go when I told him that I had already called the police. It was a bluff, but miraculously it worked, and he left. But I realized then I needed to escape this life.

A month after returning to New York, I began packing my clothes. Alfredo came in, and we started fighting, and he began throwing my clothes out of the suitcase. I put them back, and we went on like this for some time. I told him if he hit me that I would scream so loudly that all the neighbors would come or call the police, and I would tell them everything that was going on.

He was so furious that he yanked the Virgin from my neck and knocked me to the floor. But I just got up and walked out, without my clothes or my suitcase.

I called my sister and went to the Mexican Consulate. They sent me to Sanctuary for Families. They helped me get a visa to stay in the US. They also arranged a visa for my mother, who had been threatened by Alfredo and his own family of pimps back in Mexico. After my escape, Alfredo’s family denounced me to my mother and said I had run off with another man. But my mother now lives with me in New York, and our relationship, despite all we’ve been through, is good.

I don’t really know what happened to Alfredo. I think he moved back to Mexico. I am helping American authorities track him down. I hope he gets arrested. I want justice for what Alfredo did to me, and what others continue to do to poor Mexican girls.

I’m not afraid of anyone anymore.

I’m also trying to get my life back. I have a 5-year-old son, who is not the result of my past life. I need to learn English. I work in a restaurant now, but I want to go to culinary school to become a chef. This is my dream.

When I’m at home with my son, I bake cookies that I try to sell to make extra money. On my favorite cookies, I write “freedom” in big letters. After everything, I still have hope.

Now she is selling her cookies online.