This is an exercise in futility!

You can't predict the value of anything unless you have at least some information on what is going to cause that growth.
What we have at the moment is a very rough technical infrastructure with no legal or political backing.
The more I look at bitcoin, the more I see a similar path to Linux developing. Its going to take a numbers of years before it gains momentum, and then, suddenly, every is using it, because they didn't realise they were.
Everyone wants to see the numbers go to the sky, and to some extent they will, but without a time frame, and some idea of real growth drivers, your graph just looks very pretty!
If you are going to make a nice graph, you need to build in a SWOT analysis to give you a far more realistic background which will help create a very useful guide of everyone on the future direction of bitcoin.