Source: http://bishopbjj.com/ these guys did some excellent work where they deconstructed the 2012 Worlds. The report details information on techniques, results, and trends. Make sure to check out their site for a further in-depth analysis.
Be sure to also check the article on high percentage techniques in Jiu-Jitsu looking at statistics
The Best Butterfly Player In The World Shows The Exact Techniques He Used To Win The ADCC Trials With Over 50 fighters In His Bracket - In His First Ever No Gi Competition.