Yes they, include dividend reinvestment.
Over 20 years I would expect stocks to give about about 4% plus inflation, bonds about 0.5% plus inflation, cash -1% plus inflation. So that comes out to 2.8% plus inflation, which lets say is 2.2%. You should get about 5% nominal.
You'll tend to get more if you buy regularly, rebalance, select riskier definitions of stocks bonds and cash, or reduce or use more lucrative forms of "cash."