To rate above the true value.

To outnumber.

transitive verb. To rate too high.

transitive verb. To count erroneously, such that the counted number is higher than the actual number.

noun. A count{1} that is higher than the true number; an erroneously high number determined by counting incorrectly; the result of overcounting{2}.

verb. To count more of something than are actually present, or to count one thing disproportionately more than another

"Or was it due to an "overcount" of pigs in the December"

undercount