This is very encouraging chart which shows 15 millions Bitcoin are in supply and I think next year is to go mainstream right after halving of blocks will take place.We have great and prosper future together with Bitcoin.
Yes, when considering there are only 6 millions of bitcoin yet to be mined, the prosperous future for every bitcoiner is very near.
15 million must be a big mark within up coming halving. When halving will occur only 750k more coins would have been mined out.
In 25 new bitcoins reward per block era, 15million is the last big round number.
It means 16 millions coins mark will be reached with 12.5 block reward era.
Here you can find more interesting facts on this...
https://en.bitcoin.it/wiki/Controlled_supply