Keep in mind that historical data doesn't give a complete picture as to how disastrous our current real-estate downturn will become. Never before have lending standards become as loose as they have in the last 8 or 9 years, with a proliferation of negative amortization, interest only, and other "exotic" loans. The degree of scrutiny given to even prime loans is at an unprecedented low.
Thus, since the foundation for today's real-estate market is FAR weaker than ever, it's unravelling is bound to be far more severe than past experiences would indicate.