CREATE TABLE table_204_237 (id DECIMAL, "season" TEXT, "average" DECIMAL, "high" DECIMAL, "low" DECIMAL, "season tickets" DECIMAL)

how many seasons had average attendance of at least 15,000 at the stadio ennio tardini ?
SELECT COUNT("season") FROM table_204_237 WHERE "average" >= 15000
SELECT COUNT("season") FROM "table_204_237" WHERE "average" >= 15000