Government Estimate of Overseas Voters
The State Department has recently shared its current estimates of the number of US citizens not affiliated with the US Government who are resident abroad, by region. The total is the highest released to date: close to 5.25 million.
Because Americans residing outside the United States are not counted in the US censuses, this estimate, as all counts of Americans abroad, is based on a limited amount of data combined with intelligent guesswork.
The estimated figures, by region, are: Africa: 109,600; East Asia and Pacific: 754,000; Europe: 1,488,000; Near East: 586,000; South Central Asia: 97,000; and Western Hemisphere: 2,222,000, for a total of 5,256,600. A World Map with these figures updated for 2011 is available here.
Thanks to Don Johnson and AARO for sharing this information.