If you are counting down the time before you are 25 so you can be an elder....maybe you should re-evaluate your priorities? Don't mean to be rude, but seems like it's for the wrong reasons? Dunno.
I do know way back when they look at how much time you spend selling in the field service, how visible you are at meetings for field service. Then they look at maturity level. But I have family appointed an elder within a couple months of moving to another country...then moved back to the States and they wouldn't even appoint him as a MS. It all depends on the needs and whims of the BoE, CO, etc.