CREATE TABLE table_10426 ("Home team" TEXT, "Home team score" TEXT, "Away team" TEXT, "Away team score" TEXT, "Venue" TEXT, "Crowd" FLOAT, "Date" TEXT)

When the away team scored 18.13 (121), what was the largest crowd size?
SELECT MAX("Crowd") FROM table_10426 WHERE "Away team score" = '18.13 (121)'
SELECT MAX("Crowd") FROM "table_10426" WHERE "Away team score" = '18.13 (121)'