The median group of the 27 Nassau County Catholic schools would seem to be Our Lady of Victory, Floral Park, 365, St. Elisabeth Ann Seton, Bellmore, 356, and St. Joseph, Garden City, 356. With lower enrollments are Our Lady of Lourdes, Malverne, 263, and All Saints Regional, Glen Cove, 195.
The site elementaryschools.org lists grade-by-grade enrollment without giving a date of the statistics. However, an analysis of that site shows how Pre-Kindergarten enrollment at some parishes can skew the total.
The approximately 66 parishes in Nassau County have religious education programs which instructed about 43,208 youngsters, plus whatever the enrollments at Notre Dame and St. Anthony (Oceanside) are. The highest enrollments seems to have been at St. Rose of Lima, 2,695 students, Maria Regina 1,800, and St. Frances de Chantal 1,633. The median group would seem to hover around the 570's, St. Ignatius Martyr, Long Beach, Our Lady of Mercy, Hicksville, and St. Boniface Martyr, Sea Cliff.