The question is, why does the total supply exceed the max supply. If I'm not mistaken in understanding it, this is a strange thing.
I think you understand it wrong indeed the total supply cant be bigger then the maximum supply ofcourse.
It's very interesting that this Eos cant be mined If I remember correctly there was only a ICO where you could trade in your Ethereum for EOS.
And now there is a supply increase of 5% a year that will be used to make a better blockchain.