Community Percentage reports

Community Percentage reports

3 reports are available in the system to calculate community percentage based on data within the Activity Record.  I ran all three of the reports and I'm having difficulty interpreting how the percentages are calculated.

I attempted to add all notes, then use division.  I also attempted to add units and divide, but my results do not match the report results.  Do you have more detailed information on these reports and exactly how they calculate the percentage?  We would like to keep track of this information, but I want to ensure that it is correct.

These are the available reports:
CPS Percentage grouped by department Report
Community percentage report
CPS percentage report