average speed for 13 year old

[MaAz Bar]

I'm 13 and can bowl average 97kp/h (60mph) and can get to 110-115 on my best (68-71mph)
Others my age can barley get past 82 (50mph)
My line is accurate
Any ideas what to work on

 

[JoeyaRoot]

There should be a few videos online about improving your throw. Also learn why and how spinning the ball makes such a big difference.