The bears and PoS people would say that all 1.5 million were sold off on the exchanges right after being mined.
They also talk about how low the volume is.
So that would mean that a majority of the coins sold were from miners while most everyone else is buying and spending/holding.
I would say that a very good percentage of the bitcoin that has been mined over the last year were sold on the exchanges as the miners generally need to pay for their electric costs, this is the nature of PoW (and also why PoW will always work).