Betfair Historical Data

Hi guys,

Wondering if you could help me find some stats on UK horse racing. I want to find out the lowest matched prices in running for favourites and compare them to the betfair starting price. Essentially I want to know what percentage of favourites trade at least 10% lower than their starting price in running. I know there is a lot of historical data available which I could use, but I havent got the time to go through it all. Does anyone know of any source where I can get this information?

Thanks.