Answer:
With females, it is an average of 3-3.5 inches per year. With males, it is an average of 4 inches per year. You can increase these numbers by exercise, proteins [Found in meats, dairy, nuts, e.c.t. (you're out of luck if you are a vegetarian who's allergic to nuts and dairy)], amino acids (found in proteins), B vitamins (found in dairy), and stress relief (found in good karma, punching pillows, resting, laughing, smiling, positive thoughts, good relationships, and good friendships) while you were waiting for a good answer (unless mine didn't help at all) I think you might have grown a bit.