we have known that their are 210,420 blocks that had been launched.
this sentence doesn't make any sense! i think you have confused bitcoin with an altcoin that has a premine and "launches" some blocks prior to its actual release!
it was not like this with bitcoin!
For every block some new bit coins are introduced, and after every 4 years this introduction is halved. Initially 50 bitcoins were introduced;
the "halving" is not every 4 years it is every 210,000 blocks which happens to be nearly 4 years.
#On July,2010 the bitcoins released were 10,512,000 (i.e.=120240 *50)
#In 2014, the bitcoins released were 5,256,000 (i.e.=120240*50/2)
#In 2018, the bitcoins released were 2,628,000 (i.e.=120240*25/2)
so ,in present day there are 17,396,000 bitcoins in circulation, out of
all 21,000,000 which are to be launched in future.
i don't even know where you are getting these dates and numbers from!!!
https://en.bitcoin.it/wiki/Controlled_supplythe first halving happened on block 210000 in 2012-11-28
the second halving on block 420000 in 2016-07-09
the third one will happen in the future on block 630,000
(210000*50) + (210000*25) + ((508338
1-420000 +1)*12.5) = 16,854,237.5
BTC1. current block height