CREATE TABLE table_65968 ("School" TEXT, "Location" TEXT, "Mascot" TEXT, "Size" FLOAT, "IHSAA Class" TEXT, "County" TEXT, "Year Joined" FLOAT, "Previous Conference" TEXT)

How many years Joined have a Size smaller than 417, and an IHSAA Class of A, and a School of jac-cen-del?
SELECT COUNT("Year Joined") FROM table_65968 WHERE "Size" < '417' AND "IHSAA Class" = 'a' AND "School" = 'jac-cen-del'
SELECT COUNT("Year Joined") FROM "table_65968" WHERE "IHSAA Class" = 'a' AND "School" = 'jac-cen-del' AND "Size" < '417'