Welcome to the forum Bricek
I brought up this question and other stamps about what percentage of 1800 stamps have survived...I talked to a well known stamp collector and we thought probably any where from 2% to 4%..
That is the rule of thumb I went by, UNTIL I was talking to the President of BNAPS Ken Lemke last night and he gave me a name of a gentleman that did a in depth analysis about this same inquiry.
His name is David McLaughlin, Vice-President of PSSC...You can contact him at the site below..https://philatelicspecialistssociet...xecutive.htm
Or email him email@example.com
Hope this helps.