Sorry for confusing you before, but now I see what you are trying to get at. I have never seen these values before. What units are they? I don't know proportions in terms of technical units like feet or inches, only in comparison to other body parts. The 'aspect ratio' of a body stays consistent after the age of 17 and older. Those are the ages the body stops maturing so it maintain a certain ratio. Young children, especially at the age of 10, ratio changes in adulthood because they are beginning to mature. So the "aspect ratio" of a child will not be like that of an adult. To answer that question, the aspect ration DOES changes from this age onward. :( I'm sorry I could not be of more help. OH! And I am sorry for confusing you before.
I think it would be best if you searched for a photograph online for people of different ages and measure the length of each body part and such. You can use the values you get as relative values of a person at that age. This is what I used to do. I can tell you this, the aspect/relative ratio lengths of the human body DO NOT CHANGE in an age group. All adult males/females will have the same ratio. All child boys/girls will have the same ratio. Maybe with some slight differences for each as everyone is slightly different in their body type.