CREATE TABLE table_57311 ("Home team" CLOB, "Home team score" CLOB, "Away team" CLOB, "Away team score" CLOB, "Venue" CLOB, "Crowd" FLOAT, "Date" CLOB)

What is the average crowd size for corio oval?
SELECT AVG("Crowd") FROM table_57311 WHERE "Venue" = 'corio oval'
SELECT AVG("Crowd") FROM "table_57311" WHERE "Venue" = 'corio oval'