Hiya,
The stock of carp go to the low 40's, most fish are probably in the high-twenties & 30's depending on the time of year. You're looking at 36 carp in there and the water is hard, although the old adage of "spend enough time there and you'll catch" is true, as is "if you're in the right place at the right time, you stand a chance".
Tench go into double figures, with 12lb being the unofficial record. Bream hit the 18lb mark. There's a couple of Eels in there - into big specimen figures along with several 20lb Pike.
Pressure kills it, so my best advice is get confident on your rigs and bait on other waters, find the fish and avoid the rush (mid-week is best in the peak spring and autumn periods).
Don't ignore the margins, fish come out from under trees as well as open water - The weed can really put people off, but there are holes and where is is floating, the bottom is normally clear.
A Mill Lane fish fights like hell and they're all gorgeous looking - if you're lucky enough to land one take care of it.
Tight Lines & Good luck!
Rob