Two possibilities:
1.
This isn't directed at you, just a general PSA, when reporting miscategorized posts don't just say wrong forum as the reason if you can help it, because if it gets moved, but the report is still pending (which can happen), its a crap shoot whether it will be marked as bad or not.
I report in a "Should be in "Insert subforum here" ". Is that fine or do I have to do it in another way? Also, at OP, if you really hate altcoins, just keep reporting them if they get out of the designated subforums.
It's fine because if one us visits the reported topic and sees it's in the right section (maybe moved by OP, maybe by another mod), we can mark the report as "Handled", otherwise we might mark it as a "Bad report" if the report comment says "wrong section" or something like that, and it was already moved to the right section (we may think the reporter erroneously reported the post).
Holliday, looking at past reports (only from the last two weeks) I can see you typing in "wrong forum" in the report comments so maybe that was why you saw your percentage going down? Though it must have happened two or more weeks ago because looking at the five reports from the last two weeks, all were marked as correct. Dogie, your reports look OK, but again I can only check two weeks back.
or
2.
Your percentage might go down due to other report(s) that were being taken care of at the same time and that turned out to be inaccurate.