In 2012, there were 159 pick sixes according to cfbstats.com, matching the number provided at Sports-Reference.com. That’s right in line with previous numbers. The table below shows the number of pass attempts, interceptions, and pick sixes in major college football games since 2006, courtesy of cfbstats.com.
It’s pretty interesting that the interception rates in college and the NFL are nearly identical. The interception rate in the NFL was 3.1% in 2007 and 2.9% in 2011, just about what it was in college football in those years. And with the exception of the crazy-high Pick Six rate in the NFL in 2012, both leagues see about 10% of all interceptions returned for touchdowns. Unfortunately, I don’t have the data to see if the Pick 6 rate was 5% in the ’50s in college football like it was in the NFL. But my guess is the trend would hold and that there’s an inverse relationship between interception rate and pick six rate.