The deadly shooting this month in Maine has once again shone a spotlight on how frequent this type of violence is in the United States compared with other wealthy countries.

The U.S. has the 28th-highest rate of deaths from gun violence in the world: 4.31 deaths per 100,000 people in 2021. That was more than seven times as high as the rate in Canada, which had 0.57 deaths per 100,000 people — and about 340 times higher than in the United Kingdom, which had 0.013 deaths per 100,000.

On a state-by-state calculation, the rates can be even higher. In the District of Columbia, the rate is 13.93 per 100,000 — the highest in the United States. The second-highest is in Louisiana: 10.91 per 100,000. In Maine — scene of the deadliest recent mass shootings — the rates are much lower than the national average: 1.15 per 100,000. But five other states that were the site of mass shootings over Halloween weekend – Florida, Georgia, Illinois, Indiana and Texas – have rates that are higher than the national average.

The numbers come from a massive database maintained by the University of Washington's Institute for Health Metrics and Evaluation, which tracks lives lost in every country, in every year, by every possible cause of death.

The 2021 figures paint a fairly rosy picture for much of the world, with deaths due to gun violence rare even in many lower-middle income, and even low-income countries — such as Bangladesh and Burundi, which saw 0.06 deaths and 0.14 deaths, respectively, per 100,000 people.

Prosperous Asian countries such as Singapore (0.003), Japan (0.005) and South Korea (0.01) boast the absolute lowest rates — along with China, at 0.013.

"It is a little surprising that a country like ours should have this level of gun violence," Ali Mokdad, a professor of global health and epidemiology at the Institute for Health Metrics and Evaluation, told NPR. "If you compare us to other well-off countries, we really stand out."

To be sure, there are quite a few countries where gun violence is a substantially larger problem than in the United States — particularly in Central America and the Caribbean. Mokdad said a major driver is the large presence of gangs and drug trafficking. "The gangs and drug traffickers fight among themselves to get more territory, and they fight the police," Mokdad said. Citizens who are not involved are also often caught in the crossfire.

Another country with widespread gun violence is Venezuela, which for the last several years has been grappling with political unrest and an economic meltdown.

Mokdad said drug trafficking may also be a factor in two Asian countries that have unusually high rates of violent gun deaths for their region, the Philippines and Thailand.

With the casualties due to armed conflicts factored out, even in conflict-ridden regions such as the Middle East, the U.S. rate is worse.

The U.S. gun violence death rate is also higher than in nearly all countries in sub-Saharan Africa, including many that are among the world's poorest.