As someone who uses statistics on a daily basis, going full nerd is welcome.
After the release of Hesitation Marks, that album was 30% of the songs played, with TDS at 16% in 2013. In 2014 with more shows, TDS was 24%, and Hesitation Marks at 17.4%.
If you look at other years, TDS is consistently at 20-25% of the songs played. Even in 2007 when Year Zero came out, TDS accounted for 25% and Year Zero 15%.
In 2008, there were less shows, but Year Zero maxed out at 22.3%, with The Slip at 18%, and TDS at 16%.
So in this context, there's always going to be a slight bias for older material.