(CNN) The United States. Home to liberty, the pursuit of happiness and the most mass shootings in the world.

America's unique relationship to gun ownership -- enshrined as a right in its constitution -- is also in the middle of an emotional and divisive debate about the meaning of the Second Amendment of the United States Constitution. Twenty-seven words that give its citizens the right to own guns and also, in the views of many critics, helped usher in a culture that sees more of its own people killed by fellow citizens armed with guns than in any other high-income nation in the world.

Gun-related deaths unfold in tragic circumstances across the country daily. But it is often mass shootings that reignite the debate over gun control in the US and that shine the spotlight on its position as a global outlier.

Here's a look at how America's gun culture compares to the rest of the world.

The number of firearms available to American civilians is estimated at more than 393 million, according to a 2018 Switzerland-based Small Arms Survey (SAS) report.

India is home to the second-largest civilian firearm stockpile, estimated at 71.1 million.

The most updated estimates place the worldwide civilian gun cache at around 857 million, a 32 percent increase from a decade prior, when the SAS estimated there were approximately 650 million civilian-held firearms.

Firearm production continues to proliferate worldwide, outweighing the effects that gun destruction might have.

According to the SAS, the exact number of civilian-owned firearms is impossible to pinpoint because of a variety of factors including arms that go unregistered, the illegal trade and global conflict.

Seventy-two percent of Americans said they have shot a gun. Americans own the most guns per person in the world, about four in 10 saying they either own a gun or live in a home with guns, according to a 2017 Pew Center study . Forty-eight percent of Americans said they grew up in a house with guns.Seventy-two percent of Americans said they have shot a gun.

According to the survey, a majority (66 percent) of US gun owners own multiple firearms, with nearly three-quarters of gun owners saying they couldn't imagine not owning one.

Yemen, home to the world's second-largest gun-owning population per capita (and a country in its fourth year of a bloody civil war and in the throes of a catastrophic humanitarian disaster) trails significantly behind the US in terms of ownership.

When it comes to gun massacres, the US is an anomaly.

There are more public mass shootings in America than in any other country in the world.

On Saturday, a gunman who police believe had posted a racist, anti-immigrant "manifesto" online killed at least 22 people and injured two dozen others at a Walmart in El Paso, Texas, marking one of the deadliest mass shootings in US history.

Just 13 hours later, at an entertainment district in Dayton, Ohio, a gunman wearing body armor approached a bar and opened fire, killing nine people and injuring at least 31 others in a shooting that lasted less than a minute

The week before, three people were killed and least 12 others injured after a 19-year-old went on a shooting spree at Gilroy Garlic Festival in northern California.

Last February, the country mourned the deaths of 17 students and faculty members of the Marjory Stoneman Douglas High School in Parkland, Florida after a former student unleashed a hail of gunfire.

In October 2017, a 64-year-old gunman fired into crowds gathered at the Harvest Music Festival in Las Vegas, killing 58 and injuring almost 500 people. It was the deadliest mass shooting in modern US history.

An attack at the Pulse nightclub in Orlando in 2016 left 49 people dead. In 2012, 26 students and staff at Sandy Hook Elementary School were killed; in 2007, 32 lives were taken in the Virginia Tech massacre.

Such massacres continue to prompt debates about gun control.

In the wake of the Parkland shooting, some students became activists and began marching for reform, calling on lawmakers to make sure that what happened at their school never happened again. Sixty-seven new gun laws were enacted in 26 states and Washington, DC , according to a year-end report by the Giffords Law Center to Prevent Gun Violence.

But mass shootings also drive demand for more guns. And US regulations covering the sale of firearms have been looser now that they were two years ago.

In February 2017, US President Donald Trump signed a measure that scrapped an Obama-era regulation aimed at keeping guns out of the hands of some severely mentally ill people.

The original rule was part of a series of moves taken by the Obama administration to try and curb gun violence after other efforts failed to advance in Congress.

In response to this weekend's mass shootings, Trump suggested Monday that his plan to prevent future mass shootings would involve addressing depictions of violence in video games. He did not mention specific measures to limit access to firearms , other than "red flag" laws that would prevent access to people who are mentally ill.

In contrast, New Zealand moved quickly to restrict gun access, after 50 people were killed in the Christchurch massacre earlier this year. The country's parliament voted almost unanimously in favor of banning military-style semi-automatic weapons. New Zealand's Prime Minister Jacinda Ardern told lawmakers they were giving "a voice" to those killed.

In other countries, restrictive gun laws have proven to make a difference in curbing massacres. In Australia, for example, four mass shootings occurred between 1987 and 1996. After those incidents, public opinion turned against gun ownership and Parliament passed stricter gun laws. Mass shootings have become rare in Australia since the introduction of tight gun control measures.

The US has one of the highest rates of death by firearm in the developed world, according to World Health Organization data.

Our calculations based on OECD data from 2010 show that Americans are 51 times more likely to be killed by gunfire than people in the United Kingdom.

Most American gun owners (two-thirds) say a major reason they own a gun is for their personal protection, according to the Pew study. However, the majority of America's firearm-related deaths are attributed to self-harm.

Gun-related suicides are eight times higher in the US than in other high-income nations.

Globally, the US sees fewer gun-related murders than many of its southern neighbors.

According to SAS data, Venezuela is currently home to the most gun-related murders in the world (excluding active war-zones) with guns killing more than 53 people for every 100,000 of the population.

El Salvador and the British Virgin Islands rank close behind, with 52 and 48 gun-related deaths, respectively, for every 100,000 of population.

The US rate is 3.9 gun-related homicides per 100,000 people. US law enforcement agencies are not required to report on gun killings by police. Often, such incidents are recorded as "justifiable homicides," and may or may not be included in official homicide statistics, according to the Small Arms Survey.