Coin supply will only reach 100% once POS activates, this will allow us to monitor the inflation rate in real time to ensure it remains at 2% annually. This means the supply will be at 102% by September 23rd, 2015. The miners do not have the power to increase supply past 100%, due to the reserve system. This number is gathered as a comparison of the compounded reward calculated from the decay equations, and the actual money supply released into the block chain. It is to show the accuracy of the time released supply, so we can monitor the global inflation.
Here is an older graph to show the supply curves over a 10 year span. These graphs are mathematically impossible to alter by block production rate in miners, ect. This is part of the function of the Reserve System.
Currently finishing Coin Shield White Paper,Viz.