CREATE TABLE table_53710 ("Home team" CLOB, "Home team score" CLOB, "Away team" CLOB, "Away team score" CLOB, "Venue" CLOB, "Crowd" FLOAT, "Date" CLOB)

What was the Average crowd when the away team was north melbourne?
SELECT AVG("Crowd") FROM table_53710 WHERE "Away team" = 'north melbourne'
SELECT AVG("Crowd") FROM "table_53710" WHERE "Away team" = 'north melbourne'