I don't know anything about computers but one of my friends was able to transpose some results (non racing) into a graph to show the increase/decrease percentage of his survey. As Chrome Prince says, look for a progression of profit, this should effectively cancel the luck factor. Can this be transposed to a graph which would save time and also be an accurate chronicle of the results?

I presume you are collecting the race results from a TAB - does the data also show scratchings?

Out of interest, can your info identify metropolitan racing because my records indicate they may differ with non-metro.