74% of the reduction in the developing world's hunger from 1990 to 2015 is from China alone
Calculated from the 2015 State of Food Insecurity in the World:
Total change in undernourishment in Developing World from 1990 to 2015:
990.7 million - 779.9 million = 210.8 million
Change in China's undernourishment from 1990 to 2015:
289 million - 133.8 million = 155.2 million
155.2/210.8 = .736
Food and Agriculture Organization of the United Nations, “The State of Food Insecurity in the World 2015: Meeting the 2015 international hunger targets: taking stock of uneven progress,” (Rome, 2015), 8, 46, accessed June 11, 2015, http://www.fao.org/3/a-i4646e.pdf.