Closes uscogdata#36. It counts governments with rows for the requested
category, so a surveyed government that genuinely spends nothing there
is indistinguishable from one never surveyed. In FY2022, a complete
census year, Georgia reports 393 of 567 cities for Police -- the gap is
cities that contract to the sheriff.
Documents the comparison that IS valid: same category, census year vs
sample year.
Geographic totals are the expensive case cog-api#37 was filed about --
without this a caller issues one rollup per category and sums them.
The pass-through was expected to work by construction; this asserts it
rather than assuming it, including under per_capita and inflation
adjustment.
jared