FAO Food Price Index: http://www.fao.org/worldfoodsituation/foodpricesindex/en/

"It also marked the twelfth consecutive monthly rise in the value of the FFPI to its highest value since September 2011"

Chart: http://www.fao.org/fileadmin/templates/worldfood/images/home...

Historical chart: http://www.fao.org/fileadmin/templates/worldfood/images/home...