...
Current hashrate makes 10 bitcoin per week, Lets average this out over the year and expect perhaps a total of 150 Bitcoin to be mined at current rates if we get no more miners.
(150 bitcoin mined over a year) / 10,000,000 shares = 0.000015 per share.
Lol, you can't math, can you?
Protip: The difficulty is *rising*

If you think the difficulty will be the same a year from now, well...
(10 bitcoins per week) X (no difficulty increase) = 520 bitcoin, not the 150 I predicted.
Hint: I took difficulty increases into account.