CREATE TABLE table_53979 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Venue" TEXT, "Crowd" FLOAT, "Date" TEXT)

What is the size of the crowd for the game where the away team South Melbourne played?
SELECT AVG("Crowd") FROM table_53979 WHERE "Away team" = 'south melbourne'
SELECT AVG("Crowd") FROM "table_53979" WHERE "Away team" = 'south melbourne'