CREATE TABLE table_16630 ("School" TEXT, "Location" TEXT, "Enrolment" FLOAT, "Founded" FLOAT, "Denomination" TEXT, "Day/Boarding" TEXT, "School Colours" TEXT, "Abbreviation" TEXT, "In competition since" FLOAT)

How many schools have an enrollment of 850?
SELECT COUNT("Founded") FROM table_16630 WHERE "Enrolment" = '850'
SELECT COUNT("Founded") FROM "table_16630" WHERE "Enrolment" = '850'