Hi, about 12k miles on my rears now and due to change in the next couple of months, so maybe 13K miles ...not a lot but I think that's the price you pay for grip
yes the fronts have been on since I got the car over 3 years ago I've put 20k on them and they are still a long way off being changed but they are cheap tyres.
The same tyres were on the back and it used to slip all the time going around corners in the wet, so I think they are a bit hard, good for long life but crap for grip