"According to the Mexican government, there were over 47,500 documented “organized crime related homicides” from President Calderón’s inauguration on December 1, 2006 to September 30, 2011, though data from the fourth quarter were not available as of the release of this report.
"While the levels of homicide in Mexico do not nearly approach some other Latin American countries, the toll of drug related violence has been unacceptably high. At the start of the Calderón administration, there was one drug related homicide every four hours; by 2011, the worst year on record, there was one every 30 minutes. Now, roughly half of all homicides in Mexico are attributable to drug violence."

Source

Molzahn, Cory; Rios, Viridiana; and Shirk, David A., "Drug Violence in Mexico: Data and Analysis Through 2011" (San Diego, CA: Trans-Border Institute, Joan B. Kroc School of Peace Studies, University of San Diego, March 2012), p. 1.
http://justiceinmexico.files…