18-24 MONTHS 13 2 YEARS 13 3 YEARS 10 4 YEARS 7 5 YEARS 9 6 YEARS 12 7 YEARS 1 8 YEARS 2 9 YEARS 1 10 YEARS 11 11 YEARS 9 12 YEARS 9 13 YEARS 1 14 YEARS 11 16 YEARS 11