All globally?
Less than 10.
Less than 10.
Not only are agents likely to be using the chip, self-service immigration gates have become really popular at airports around the world and mostly use the RFID chip together with a face scan
2. Make a fake passport with your photo (and fingerprints etc.) and add the AA key so that it passes the check
You'll still have to somehow fake Passive Authentication (in which your data, including photo, is signed by the country's public key) too, though.
Supposedly it's surprisingly (or maybe not, given how international government relations historically work) difficult for countries to exchange their public keys: Since there isn't any central authority, nor a chain of trust available (a la "this key is signed by France and Switzerland, so it's probably the real thing to us, Germany"), it boils down to n^2/2 key exchanges, and n additional ones every time a single key expires or, worse, has to be rotated on short notice. Then all of that has to be distributed to all border authority systems.
Last time I looked into this (10+ years ago), my laptop doing Passive Authentication and Active Authentication using 10 lines of Python and my country's root certificate (it's publicly available) was supposedly more than what most border checks could practically do.
It seems to be publicly accessible too. Maybe I'll add a few lines to my script if I can still find it :)