Last year about 15%- but I made a couple dumb moves, an paid the price <bg>. 2003 was my best year. 117%. overall average for the last 5 years: around 35%
But, I feel if you are beating the market averages (around 11%), then you are winning the game. So- compare your plays to that- find a system that works for you to beat the market, imo. Then you can tweak it from there.