Long Term market returns

I got an email from AAII today detailing the long term performance of the market vs. bonds over the past 10 years. If the link is accessible the full info is here:

10 year returns (I assume these are annualized returns over past 10 yrs, but not sure. Also not sure of how benchmarks are defined.)

Large cap stocks 3.43%
Mid Cap stocks 8.48%
Small Cap stocks 5.70%
International stocks 5.60%
Emerging Markets 13.06%

Intermediate Bonds 6.67%
Short Term Bonds 5.70%

It's very interesting to me that bonds have performed comparably to most equity classes over the past 10 years.