DASH: Total supply out by 5M DASH?

I'm analyzing the current supply of DASH.
According to the original whitepaper, the first year had cumulative block rewards of 1'000'000 DASH per year. After that the reward were reduced by 7.14% every 210240 blocks and will continue to do so in the future. That's a relative easy calculation and adds up to roughly 14M DASH in the year 2218. However, according to this website and coinmarketcap, the total supply is 19M.

Then I found the below picture and see that Dash started with 5 Million in circulation. Where are those initial 5 million DASH?

As far as I know DASH was a fork of Bitcoin in Jan 2014, it started as Xcoin, then became Darcoin and then DASH. I can't find the 5M DASH in any description though... Can someone explain this?

Thanks for your help