CREATE TABLE table_15923 ("Season" TEXT, "Network" TEXT, "Season premiere" TEXT, "Season finale" TEXT, "TV season" TEXT, "Ranking" TEXT, "Viewers  ( in millions ) " TEXT)

The season premiere aired on September 11, 2000 aired on how many networks?
SELECT COUNT("Network") FROM table_15923 WHERE "Season premiere" = 'September 11, 2000'
SELECT COUNT("Network") FROM "table_15923" WHERE "Season premiere" = 'September 11, 2000'