CREATE TABLE table_11515 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Venue" TEXT, "Crowd" FLOAT, "Date" TEXT)

In the game with the venue of mcg, what was the attendance?
SELECT "Crowd" FROM table_11515 WHERE "Venue" = 'mcg'
SELECT "Crowd" FROM "table_11515" WHERE "Venue" = 'mcg'