The blocks have been mined at a substantially faster rate than the ideal of 6 blocks per hour. I think the average is more like 7.5 blocks per hour, which pencils out to 65,700 blocks per year and 1,642,500 btc per year.

Using the 2.5% to 25% range, I get 0.10 to 1.02 bitcoins per share in potential mining revenue.