Amateur radio operators by country

[k4kyv]

Not sure how "recent" this is, but FWIW

http://www.nationmaster.com/graph/lif_ama_rad_ope-lifestyle-amateur-radio-operators

So much for the argument that we have to have more severe sub-band restrictions in the US than anywhere else in the rest of the world because US amateurs outnumber all the other countries of the world combined, and that those restrictions (particularly on 40m and 20m) are needed to keep the bloody yanks from overwhelming the bands with our QRM.

[Pete, WA2CWA]

This indicates (chart on right side of page) dates of the data: http://en.wikipedia.org/wiki/Amateur_radio_operator