First Class Mail / All Mail / First Class Mail Per Capita / All Mail Per Capita

As in the case of telegraphic communication, the coding criteria call for the exclusion of foreign sent/received and in-transit items, although in cases where official government figures are used, at least some foreign items appear to be included.

Newspapers carried by mail are included as bona fide (non-first class) postal matter, but since figures for the latter are occasionally lacking, some discrepancies are to be expected in the "all mail" category. Post cards are, of course, construed as "first class" items and prior to World War I constituted a large part of the latter class of mail in many European countries (most notably Germany.