Keep in mind that the period 2000-2015 includes two major recessions. Almost any other fifteen year period will work even better (you can test it on that websit

Keep in mind that the period 2000-2015 includes two major recessions. Almost any other fifteen year period will work even better (you can test it on that website). Move the timeframe to 30 years (which is the bare minimum that the early retirement crowd looks at) and it's difficult to find a period with less than 7% returns. Even adjusting for inflation, it's rare to have a 30-year period with less than 4% returns, which is the basis for the 4% Rule mentioned in the article.