How old do you think the Main cast is?

I think Fluttershy is the oldest but not for to much, they all must be betwen 15 or 20 but its a funny thing to talk about so i want to know what do you guys think.

For me is like this


Apple Jack.17


Rainbow Dash.16

Twilight Sparkle.16

Pinkie Pie.16

and Spike could be 10 or 12 years i think.

OK now your opinion.