CREATE TABLE table_4485 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Venue" TEXT, "Crowd" FLOAT, "Date" TEXT)

How big was the crowd when the home team scored 20.21 (141)?
SELECT MAX("Crowd") FROM table_4485 WHERE "Home team score" = '20.21 (141)'
SELECT MAX("Crowd") FROM "table_4485" WHERE "Home team score" = '20.21 (141)'