I think that the number is bigger, since some have posted them as images which you could not "scan".
My list is indeed not complete. I didn't search for Hex keys either, only WIF.
in some cases I remember there was a scam spree of posting "by mistake" ETH private keys for wallets
I didn't search for altcoin private keys.
for some addresses the number of transactions was too big and the Electrum servers were cutting me off
That must be why the wallet grew to 2.2 GB.