Here's my view:Pan starts off at age 14. do we agree on this baseline?
when she stows away, she's 14 years of age
they spend an entire year, short a few days, in space
they collect the dragonballs. they come back to earth, and she's 15
so she's 15 when they come back to earth
but OH NO! Bebi is there! he possesses everyone and "kills" Goku. then he takes the dragonballs and MAKES A WISH!!! He makes a NEW wish on the black star balls, for Planet Tuffle to be destroyed, and WOOSH , the balls are off again
a whole year passes, then. we know because Goku is training up with the Kais (pfft yeah right training, ifyou call grinding coffee working out). Before you know it, a huge new space cruiser is built, tons of people are transferred to planet tuffle, bebi has set up his new establishment, and Goku comes back, fights him, and OH NO! EVEN THOUGH BEBI IS DEAD, the worls is about to eXPLODE!
= 1 year has passed
so Pan is 16
but we keep going!
then peacetime comes. long enough for them to rebuild things, get life in order, organize the next tournament, life is good, people are happy
lets say at MINIMUM 6 months
so pan would be 16 1/2 minimum, right?
then hell opens up
they battle for a whole day, defeat android 17 within 24 hours, and then..... oh NO!!!! thy need to find the DRAGONBALLS again
lets say 3 months minimum
making Pan 16 years 9 months..... uh oh, only 3 to go! and we still have an other saga
if Frieza... if defeating Frieza and his gang took 4 months... then I am CONVINCED that defeating 7 dragons 1000 times more powerful than frieza would take at least that long
lets say 3 months
at minimum, Pan would be 17
however, I like to think that peacetime lasted a whole year instead of 6 months
making her 17 1/2
and I also think she was just over 14 when goin gon the trip to space... so 14 1/2 woul dbump her to 18
Pan, at the end of GT, shoudl at least be age 17, and at max, 18
Starts at 14
+ just under one year in space makes 15 (I'm taking the different view to her in that the Black Star balls didn't reset when returned to earth, thus making it excactly one year when Earth goes boom. I also find it unbelievable that Goku spent a year grinding one cup of coffee o_O)
The 'peacetime' could have lasted a few weeks to a few months, we can't be sure can we? It wasn't long enough for Bulma to change her hairstyle, lol... we can't gauge this time by Android 17's double's construction as Dr Myuu had been long dead at this point.
I don't give any time at this point for the dragonballs to be gathered, given the speed the Z-fighters have shown in the past in gathering them.
I'm also pretty sure Goku fought the evil dragons consecutively. (straight after this attempted wish) as the very world was in danger from its' aura) and it is noted in the final battle that Goku has been fighting for ages.
So, that's her 4 years, versus my year and a few months. *smirks* Now we're all fans here... lets dog-pile on this topic and throw our views and know-how in! (it's tasty, y'gotta' admit)