Why was there not a great deal of cartel violence in Mexico before 2006 even though 90 percent of the Cocaine coming into the U.S. was transiting from Mexico at that time?

CJM 331 WEEK 2: Chapter 1: Mexican Cartels: A Century of Defying U.S. Drug PolicyChapter 1: Mexican Cartels: A Century of Defying U.S. Drug PolicyWhy was there not a great deal of cartel violence in Mexico before 2006 even though 90 percent of the Cocaine coming into the U.S. was transiting from Mexico at that time? What does this say about Mexican policy since 2006?NOTE: MORE THAN ONE ANSWER POSTED CHOOSE ANYONE