Currently the Report view shows total per month (across categories) + average between categories (basically Total per month divided by # of non-blank categories). This is the bottommost line of the report.

I fail to see the fit of this "average" line for any use-case. Does anybody use this number for anything useful?

You may consider removing this lowest line, only keeping Totals at the bottom of the report. Note, between months (for the same categories) both Total and Average are very useful