Over the past decade, Panama has adopted some of the strictest smoking laws in the world. In 2008, the country banned smoking in nearly all public spaces, indoor and out, as well as all workplaces and sports venues. That same year, it became the first country in the Americas to ban all advertising, promotion or sponsorship of tobacco products. It also requires 60 percent of tobacco packaging to be covered with health warnings.

These efforts helped Panama become the No. 1 nation at cutting smoking prevalence over the past 15 years, bringing the estimated number of smokers down to 191,200 this year, according to a World Health Organization report released Wednesday. The report details estimated smoking prevalence by country every five years starting in 2000, with projections through 2025. To figure out which countries had seen the biggest improvements, I calculated the percentage change in smoking prevalence from 2000 to 2015. Panama topped the list, with a 57 percent decline. I also calculated the percentage change projected from 2015 to 2025.



India, though it has more than 101 million smokers, now has 37 million fewer than it did 15 years ago, the largest drop in number of any country (India had the sixth-largest percentage decline in smoking prevalence).

Among the 26 countries that have seen an increase in smoking over the past 15 years, 16 are low-income countries in sub-Saharan Africa.

The biggest increase in smoking is in the Republic of Congo, where the WHO estimates that smoking prevalence jumped from nearly 6 percent in 2000 to 22 percent in 2015 and expects that number to climb all the way to 47 percent by 2025. Cameroon, Bahrain and Niger also saw increases of more than 100 percent over the past 15 years.

In East Asia, Indonesia is the only country to see an increase (though given its population, that increase is equal to nearly 30 million people), while in the Americas, Haiti was the lone country with an increase in smoking prevalence.

The 10 countries with the biggest decreases in smoking prevalence span continents and GDPs. Iceland and Norway, wealthy countries with strong public health systems, are second and third for biggest declines in prevalence, while Myanmar comes in fourth. While the WHO projections show Myanmar continuing on a downward trajectory, some inside the country are worried that a recent lift in sanctions is ushering in Big Tobacco.

Meanwhile in Uruguay, which holds fifth place, smoking prevalence dropped by nearly 50 percent over the past 15 years and is expected to decrease to just more than 14 percent by 2025. But the South American nation of 2.7 million is currently embroiled in a battle with Philip Morris, which claims that legislation requiring 80 percent of cigarette packs to be covered with health warnings is devaluing its “legally-protected trademark and brand.”

Uruguay has been getting help from the foundation of former New York City Mayor Michael Bloomberg to pay for legal fees in the lawsuit. And soon it may not be the only one; Bloomberg and Bill Gates announced a $4 million fund Wednesday to help developing countries fend off legal challenges from tobacco companies.