Probably not by much. It may be a bit different due to inbreeding and genetics of one fish vs. another, but it shouldn't be drastically different. It's mostly keeping them in the right conditions that will allow them to live out their full lifespan.
Actually it can range anywhere (depending on how badly inbred) from 1 1/2 years to 4 years. That is quite sad. That means that some give birth a few times then die, not even reaching full adult size