The population of Syria is 17,951,639, according to the CIA World Factbook.

That figure (oddly identified as a “July 2014” estimate) is wrong, according to everyone else.

The discrepancy was noted yesterday in the intelligence newsletter Nightwatch.

“NightWatch consulted six separate sources for the total population of Syria. They agreed that it is between 22 and 23 million people, not 17.9 million as indicated in the CIA World Factbook. There are about 7 million Syrians under voting age of 18 and more than 15 million registered voters,” the newsletter said.

“NightWatch relies on the CIA World Factbook as a standard reference for unclassified factual, baseline information, as does the Intelligence Community. On three occasions since 2006, NightWatch has found errors in the Factbook,” the newsletter added. “This was the third occasion.”

A Congressional Research Service report last month also cites a total Syrian population of “more than 22 million.”

Errors, of course, are to be expected– even, and especially, in intelligence publications. One great virtue of the CIA World Factbook is that it is a public document. This makes it possible for readers to identify such errors, to draw attention to them, and to promote their correction.