CREATE TABLE table_37339 ("Track" TEXT, "City" TEXT, "State" TEXT, "Opened" TEXT, "Major Series" TEXT, "Turns" TEXT)

What shows for opened for the Nascar Major Series?
SELECT "Opened" FROM table_37339 WHERE "Major Series" = 'nascar'
SELECT "Opened" FROM "table_37339" WHERE "Major Series" = 'nascar'