3rd percentile for boys at 12 years old. https://www.cdc.gov/growthcharts/cdc-charts.htm https://www.cdc.gov/growthcharts/cdc-charts.htm In NSW the guide is th

3rd percentile for boys at 12 years old. https://www.cdc.gov/growthcharts/cdc-charts.htm https://www.cdc.gov/growthcharts/cdc-charts.htm In NSW the guide is the person should be > 145cm which is somewhere between age 9 and 14 for girls. https://www.transport.nsw.gov.au/roadsafety/parents/child-car-seats https://www.transport.nsw.gov.au/roadsafety/parents/child-ca...