@MartinSleziak I don't know. If I where you I'd ask in CRUDE, or someone of the Smokedetector Charcoal HQ crowd. (Actually the former somewhat achieves the latter.)

If I run into somebody I'll try to remember to ask.

@MartinSleziak some unofficia number is 195 for MO and 227 for math.se over the last year. Which is relatively a lot more for MO. Such data can be obtained from the web dashboard of smokedetector see metasmoke.erwaysoftware.com via "search" (I did not try it yet though.)

I suppose those are only results from SD, but that is probably a good approximation of total spam posts.

Yes, I'd guess so @Martin But SD also has a category "manually reported" I am not sure if those are flags or some specific report though. The very active math user currently known as Bookend ought to know though.