Hi Chris,
Usually around 50% but I cant tell you exactly as I am never there the whole day(unless its a rare losing one). I am a firm believer in getting my $ and getting out,dont push lady luck too far,and I dont care what anyone else thinks that is a major part of this business.
Most punters half worth their salt are ahead sometime in the day.
It all depends what you are there for, a day out,get ********ed with your mates, or to make money.
If you are there to make money,then set a target and if you reach it go home,or as I do have one more bet if that gets up have another until a losing one.
The main thing too(and Im not being a smart ********)you cant take home a $1000 profit with $20 bets.

Cheers