According to data from Blockchain.com, the total number of BTC tokens that have been mined reached 17,992,413 on Oct. 14 at 00:00 AM UTC, meaning that the 18th million BTC will be mined during the following days. Roughly, this is 85.7% out of Bitcoin’s total supply of 21 million tokens.
Mining and processing power of the network has also consistently seen a steady growth in 2019, with the Bitcoin hash rate reaching a new all-time high of 108.46 TH/s on September 26th. At the time of writing, the latest reports have the Bitcoin hash rate at 87.29 TH/s.
However, the projected date for the mining of the last Bitcoin is the distant year of 2140. This means that the remaining 3 million Bitcoins will be released over a period of more than 120 years.
Every ten minutes or so, a new block is validated on the blockchain, which rewards miners with 12.5 BTC. Once the next Bitcoin halving takes place (in more than 30,000 blocks at the time of writing, roughly 211 days), miners will be rewarded with 6.25 BTC. This will keep happening every 210,000 blocks, which will make these remaining 3 million BTC much harder to mint.
Block reward halving is not the only thing that will make Bitcoin scarcer with time, as there are probably millions of Bitcoins that have been lost due to deaths or accidents where private keys have been lost or forgotten.