What is the run of the mill age to stop growing?

What is the normal age for relations to stop growing in elevation? how come some people stop growing close to at 14 and others stop growing like at 21? what factor determine the age to stop growing?
Why did I stop growing at 12 but I have friends who are 21(my age) and are still growing? could I still verbs to grow? what can I do to grow more?What is the run of the mill age to stop growing?
most people stop growing at 18
the nornal age to stop growing is 21. i own afrans who stop growing at the age of 21.so i thing 21 is the second growing age.