It really depends on how you drive it, I had a '94 Honda Accord with over 100L miles and it was a non-hydraulic clutch and it only needed adjustments done. I think with hydraulic clutches the only way to know if you need a new one is if it's grinding when trying to put in in gear and/or releasing the clutch.

My clutch felt odd at first so I took it to the Chrysler dealer and he told me unless it's grinding then it's probably fine.

Also, clutch replacements will be far cheaper than replacing the whole tranny on the automatics.