Kai (Ninjago)

So, one day I was going through all the threads on this wiki when I came across the one that was about how old Lloyd was. And i had been wondering this question for a long time, so I thought about asking this question in that thread(And I kinda did) but I thought that it deserved it's own thread. After all, I have always thoght that Lloyd took the spotlight away from the other ninja (not that I don't like him. He's awesome, especially in his elemental robes). So, about how old do you think the ninja are. Oh, one more thing. On the other thread that I mentioned above, there was a reply that Cole was like 14. So I'm also adding on the question of who thinks that's cannon.