Here are some updated stats:

Membergroup	Average accuracy
(all)	60%
Newbie	51%
Jr. Member	52%
Member	54%
Full Member	59%
Sr. Member	63%
Hero Member	73%
Staff	88%

In all, there have been 27,689 good reports, 8129 bad reports, and 1067 unhandled reports.

I think that this is all pretty good! Any accuracy percentage above ~25% is probably fine.