I think it's past time for another Stupid Questions thread, so here we go.
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Please respect people trying to fix any ignorance they might have, rather than mocking that ignorance.
I could be confabulating, but I have a memory of that threshold being involved in an survey from a few years ago.
A quick C-f through the surveys (or, at least, Yvain's censuses) would indicate the threshold was 100 in 2012.