Bingo. Any one fat and sedentary and over 60 is living on luck. Your numbers may not come up soon, but there's a good chance they could. What's the latest on how many after A Dance with Dragons? 2 more isn't it? At 5 years a book it's a 50-50 bet he'll finish his series at the current rate.
And its probably even less likely that he'll keep it to 2 books given what happened with Dance.