How do factbook read counts work?

[Sliabh Grianas]

When one of my factbooks says it has however many reads, does that count all of the times I’ve read it, or do I only count once, and the read count represents the number of different countries that have read it?

[Russian Brotherhood]

Only once

[Riemstagrad]

Only once

A simple test reveals that it does count doubles. Refreshing the page increases the read-counter.
Don't exploit it, people saw their nations deleted for inflating their read-count. (Although i must admit, the case that i have in mind was rather extreme).

Edit: It only counts different nations then your own.