24 3–3.5 yrs 25 3.5–4 yrs 26 4–4.5 yrs 27 4.5 yrs 28 5 yrs 29 5.5 yrs 30 5.5–6 yrs 31 6 yrs 32 7 yrs 33 7.5 yrs 34 8 yrs 35 9 yrs 36 37 38 39 40 41