From here, we can read that :
A private key is a 256-bit value, meaning there are approximately 1.1579e77 possible keys (There are about 1.2288e66 invalid values
But here, we have :
Nearly every 256-bit number is a valid ECDSA private key. Specifically, any 256-bit number from 0x1 to 0xFFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFE BAAE DCE6 AF48 A03B BFD2 5E8C D036 4140 is a valid private key.
Does "nearly every" mean (1.1579e77-1.2288e66) out of 1.1579e77 ?