[Koha] Another report request -- Active Cardholders

[Cab Vinton]

There is a promising report on the Koha wiki (List Active Patrons by
Category for a Specific Month). However, it doesn't seem to be
providing valid results, even after changing "old_issues" to "issues".
(The latter change produces counts in the single digits.)

We're looking for a count of active borrowers between two dates,
broken down by categorycode. ("Active" meaning at least one checkout
between the two dates.)

Appreciate any help!

Cab Vinton, Director
Sanbornton Public Library
Sanbornton, NH