POPULATION BY SEX AND AGE : Total 2010 Census Population for NEW ROCHELLE, NY: 77,062: 100.0%: Under 5 years: 4,696: 6.1%: 5 to 9 years: 4,754: 6.2%: 10 to 14 years: 4,949: 6.4%: 15 to 19 years: 5,855: 7.6%: 20 to 24 years: 5,371: 7.0%: 25 to 29 years: 4,789: 6.2%: 30 to 34 years: 4,906: 6.4%: 35 to 39 years: 4,862: 6.3%: 40 to 44 years: 5,208: 6.8%: 45 to 49 years: 5,569: 7.2%: 50 to 54 years: 5,405: 7.0%: 55 to 59 years