6% over 10 years is 81.9% return isn't it? Assuming 0.5% per month compunded 120 times.Would your analysis show how often in the past 10 or 20 years how often would the gain be more than a fixed bank deposit; I expect about 6%.
Between 3/Jan 1928 and 6/Nov 2009, the frequency of S&P500 2520-day returns (before dividends) exceeding 81.9% is 55.5%.
For 5040-day returns (20 years), the frequency of beating 6% improves to 94%.
For 7560-day returns, the frequency drops back to 63.4%. That's surprising.
Keep in mind this is all before dividends.