The period since 2006 has witnessed unprecedented food commodity price developments. Between September 2006 and February 2008, world agricultural commodity prices rose by an average of 70 percent in nominal dollar terms, with prices in some products rising by much more than that. The strongest price rises were observed in wheat, maize, rice, and dairy products. Prices fell sharply in the second half of 2008, although in almost all cases they remained above the levels of the period just before the sharp increase in prices started.
Sarris, A. "International responses to vulnerabilities of developing countries to food commodity price risks" Ferdi, policy brief B89, March 2014