Denise,
Your current betting ($1EW) is the best course of action - bet what you can afford to lose because there is no certainty that your system will continue to return a profit. You can process whatever amount of past data but it is no guarantee of success at tomorrow's punt. People here seem to lose sight of the fact that the only long term winners at the punt are the tote and the bookies, and the the books are baling out because of dwindling returns.