I got that and although this are just random figures I would agree to 1000 (+/- depending on the kind of object talked about) but if the number of objects is known to be less than 1000 or very close to that in my understanding a share of some 50% would do to rate a tag as “de facto”.
Anyhow as long as there is no guideline for that I understand these figures are just personal estimations.
“90% of all” is for catching things like capital=yes (capital of a country) where mapping 1000 of them is impossible as there is less than 1000 countries.
But anyway it is not some God-given-guidance, just some rough numbers that would be entirely sufficient for me.
+60%