Its great to be able to use this chart as a baseline for future developments to come. Thank you for putting this up for public viewing.
I don't think you should rely on history when it comes to future price
The graph shows inflation against time - I'm not sure where you're seeing future price?
More specifically, the graph is based on block reward reductions. We don't know exactly when these will occur (they occur every 410000 blocks, and each block should take approximately 10 minutes on average) but we know that they will occur. We know, for example, that the block reward will be reduced to 12.5 BTC per block (from 25 BTC per block) in the next few months. We don't know exactly when, because it depends on how fast blocks are found, but we know to within a few weeks.