Is this fast growth for a nearly 13 year-old boy?

[dragon_fly_7]

My young brother will be turning 13 on May 5th and it seems like he's adding cms in a rather quicker pace.

 

He's now 5'6 and in cms that would be like 1.68 meter.

 

My parents are respectively 5'4 and 5'11. I'm just slightly above average at 5'7 (well I'm a woman).

Edited January 21, 2015 by dragon_fly_7