It's not the average it is the range that is considered normal.
Average is something completely different, if the average person is dying does not mean that you want to be average, if the average person in Australia is obese does not mean you want to be average, but you want to be in the healthy range, not average.
You are well within that range, even at 11 you are still within that range.
Plus your blood test is nothing but a snap shot of what it was that second when your blood got taken, your readings this minute or even an hour afterwards could be and most likely are completely different.
Your blood and hormone reading will change minute to minute all day long, depending on time of day, stress, what you have eaten, what you are doing, what you are experiencing, how you feel etc etc