comeback statistics

Does anyone know where I might find stats on the following please?  It's commonly said that 2-0 is a hard lead to defend, and often worse than 1-0.  It certainly seems to be true for my beloved Coventry City, but I wondered where I could find percentage stats for teams coming back to draw or win from being 2-0 down, and if there could be any betting value there.  I don't know the best site to go to.