Miss D, 'per capita' (literally, per head, or person) is a benchmark used to mormalize statistics for comparison purposes, per captia income, or violent crimes per 100,000 residents, etc. The "How to Lie" book is a great reference.
Verily, DC, for all the carping about over 600K denied, they make no mention of the fact that the massive majority of those denials are due to simple mistakes - i.e. same name/different person, misspellings, clerical errors, and other innacuarcies. The telling part is the less than 300 arests and a dozen convidtions - the Feds just don't walk the walk ('cept when it suits them).
Curtrent scandal here'abouts is the number of women getting assaulted by significant others who shouldn't have access to guns because of restraining orders/domestic violence stuff because the local juristictions (in MD) can't seem to get their names into the database in time (they're literally months behind). Yet another good example of the how well 'the law' will protect you (not)>
M2