I Am Begining To Worry About The Size Of My

i am begining to worry about the size of my 6 year olds head. he was born with a big head and it grew really fast but due big head running in the family it wasn't that big of an issues. i'm including his growth chart from when he was little he was born 6/26/12......is this something i should really worry about? i do not know what his circumference is right now but it is bigger since the last measurement.
Name     Height (ft & inches)     Weight     Head Circumference     
7/10/2012     1' 7.75"     6 lbs 14 oz     36.8 cm     
8/31/2012     1' 10.75"     10 lbs     40.6 cm     
10/29/2012     2' 0.6"     13 lbs 4 oz     43.2 cm     
3/26/2013     2' 2.5"     18 lbs 15 oz     47.6 cm     
10/3/2013     2' 7.299"     25 lbs 11 oz     50.5 cm     
1/7/2014     2' 8.559"     26 lbs 8 oz     82.7 cm