The smallest 30 % of stocks did the best, with average annual gains of 12.3 % from 1960 through to the end of 2013. (moneysense.ca)
There is a really interesting study that shows how only a few days in a year will contribute to the majority of annual gains in the market (chart below). (ourfinancialpath.com)
To date, the passive index fund averaged annual gains of 7.1 % and the five actively - managed funds returned an average of only 2.2 %, compounded annually. (ourfinancialpath.com)