Per person, the world produces 15 percent more calories than in 1970
"Per person, the world produces 15 percent more calories than in 1970; and at least 20 percent more agricultural output compared to 1980."
Food and Agriculture Organization, Food Supply Per Caput Per Day World Total 1970-2000, http://www.fao.org/es/ess/chartroom/chart.asp?image=img/charts/73.gif Food and Agriculture Organization, Food and Agriculture Statistics Global Outlook, June 2006, 1. http://faostat.fao.org/Portals/_Faostat/documents/pdf/world.pdf