Agreed to some of extent, but how about include them also?
For example, I want to improve my reporting to have a 100% and my reports are 50% bad. How could I improve it without seeing it?(Just an idea because I would like to report regularly once I bump into one of them)
Striving towards 100% is a good attitude, but honestly anything more than 60% is considered good. Your nearly there!
I don't know the number of reports you would have to make for it to appear, but I'm assuming you could just watch the posts after reporting them or if you haven't reported that many your accuracy is likely going to fluctuate a lot, and you can judge whats correct or not from that. By the time your percentage doesn't change all that much you'll probably have access to the more in depth stats.
On my main account I have tonnes of bad reports probably the most on the forum don't worry to much about it. The community would prefer you to make reports you are unsure about rather than ignoring a post that requires an action.
If the deciding factor of reporting a post or not is because of your accuracy you are doing it all wrong. This I'd why moderators are there to review your report and I'm sure they don't mind having bad reports.