Sorry, that chart is lying. Werepossum insists that no conservative groups were approved, and he's never wrong about anything.
/s
That's good information, but note that it's not the whole story. There are only 111 groups listed, while TIGTA reviewed 297. The list above apparently only covers applications targeted due to keywords in the groups' names. The ideology of the remaining 186 groups is not shown.
In other words, we don't know the total ratio of conservative to liberal groups pulled. TIGTA declined to classify the non-keyword groups. I'm not aware of anyone else who's reviewed the whole list, probably because I don't believe the whole list has ever been released. The only definitive word seems to be the IRS received significantly more conservative political applications than liberal political applications. I've also read the ratio was about two to one, but I don't remember where, and I won't claim it's accurate. It may just be someone's off-the-cuff guesstimate.