[ansel12]

“French libraries are said to file their nation’s constitutions — there have been more than a dozen since 1789”

Off topic, but why do writers do that, “there have been more than a dozen since 1789” why not just use the actual number?

[USFRIENDINVICTORIA]

"Off topic, but why do writers do that, “there have been more than a dozen since 1789” why not just use the actual number?"

I'm going to hazard a guess -- the majority don't know what the actual number is. Most of them are too lazy to do any research on the topic. Scores of others just don't think precision matters. (irony intended)