Also presumably these are exploits to burn - lower value exploits for whatever reason.
E.g. once an exploit is detected by Apple, you might as well use it. Or an exploit that only relevant to an iOS version with low install base - just use it.
I guess Apple could go back and look at their crash report telemetries to determine when the exploits were active. Google doesn't have that type of historical data for iOS devices. Of course there were no mentions of that as evidence.