The actual number of Bitcoins, 20999999.9769, differs from the so-called 21 million by 0.0231, or 2.31 million Satoshis.
The total mining output of Bitcoin in the last three mining cycles, from 2128 to 2140, for a total of 12 years, is: 0.0084+0.0042+0.0021=0.0147, which is much less than 0.0231
If: The total output of Bitcoin in the last three mining cycles + the output of the third mining cycle from the last is:
0.0084+0.0042+0.0021+0.0084=0.0231 (exactly equal to 0.0231)
In other words, the number 21 million means that Bitcoin production has increased by 12 years + 4 years, for a total of about 16 years.
Bitcoin has only been around for 15 years and 3 months.
So 0.0231, can it really be ignored, can it really come out of thin air?