Perry, since attrition is apparently new to you and it appears that the only time you've observed it was at Alabama, why don't you check out Ole Miss. There should be some interesting number crunching going on there this offseason.
When you're done you could look at your own program. If you're still interested in attrition when you're through with that you could look at every other football program in the entire country. You might become educated and find that attrition in every program is both inevitable and a necessity.