China allegedly executed 2,400 people last year, roughly three times more than all other countries' death penalties across the globe combined, according to the human rights group Dui Hua Foundation. The findings by the U.S. group suggest China, home to one-fifth of the world's population, has continued to kill people in large numbers even as Chinese leaders have reduced the number of annual executions from 12,000 in 2002.

John Kamm, executive director of the Dui Hua Foundation, told the Telegraph the downward trend was "the single most positive development in the field of human rights in China in decades." Dui Hua's findings are based on state media reports and intelligence from sources. Chinese authorities treat executions as state secrets but have occasionally alluded to the killings in the past. In 2012, a deputy health minister cited the fall in executions as contributing to a shortage of transplant organs. 

It's unclear why China is scaling back on executions. In 2013, 39 percent of death penalty cases reviewed by China's Supreme People’s Court were sent back to higher courts for more evidence, according to Dui Hua. In one case earlier this year, a survivor of domestic violence sentenced to death for killing her husband had her verdict overturned. China uses the death penalty as punishment for 55 offenses, including “counter-revolutionary crimes,” treason, embezzlement, drug smuggling, money counterfeiting, rape and murder, according to the Independent.

Only 22 countries carried out death penalties by beheading, electrocution, firing squad, hanging and lethal injection in 2013, including Indonesia, Kuwait, Nigeria and Vietnam. In 1993, 37 countries enforced executions. The United States, the only country in the Americas that performed executions in 2013, carried out 39 executions last year, down from 43 in 2012. 

China's executions far outnumber that of any other country. Across the globe, executions grew by nearly 15 percent in 2013 compared with the previous year, largely because of an increase in deaths in Iran and Iraq, according to a March 2014 Amnesty International report. The total number of executions for the rest of the world was 778 people in 2013, according to Amnesty International. Amnesty has not published statistics on China's death penalties since 2009 due to the difficulty of getting information, according to Al Jazeera.