so they mine for themselve since about 3 years?

are the figures above correct?
Year Coin supply Inflation
1 470426769731536 180.015934364
2 725516828588937 54.2252429646
3 940676990098927 29.6561227847
4 1122157371491044 19.2925290299
5 1275229809050507 13.6409064761
6 1404340975270235 10.1245411065
7 1513241532111717 7.75456664437
8 1605095069693740 6.06998523586
9 1682569994083979 4.82681218409
10 1747913757492611 3.88356880477
11 1803028628435353 3.15318022451
12 1849516235066977 2.578306628
13 1888726978324850 2.12005401815
14 1921799891692961 1.75106904003
15 1949695723833590 1.45154718039
16 1973224843465019 1.20680982903
17 1993070776474089 1.00576135937
18 2009810059460965 0.839873986637
19 2023928395353035 0.702471152715
20 2035836535103161 0.588367640746
Generally premined coins are part of block subsidy for genesis block, so when that block will be mined by devs to start the chain, they will have 8% of 21 million coins. Later on they will send it to airdrop participants & keep 420,000 coins as a compensation for last 3 year of work they did. That is how it generally works.