stock clutch

does anyone know about how long a stock clutch lasts? i've got about 46K on my car. i bought it used with 33k, so i guess i've put about 13k slightly harder than normal miles on it. lately it just hasn't felt like it used to. (or maybe it's because i drove a prelude with a nice act clutch in it... mine feels like mush when i push down on it now )