This picture is a screen shot of a WAMU Alt-A mortgage pool. This pool was originated in May 2007 and was 93% rated AAA. This is not a subprime pool. These are mortgages sold to people with on average a 705 FICO score.
Take a look at how poorly this pool of mortages is doing. As of this week 25.3% are 60 days or more delinquent. 13.35% are in foreclosure and 4.44% are REO.