SELECT "Crowd" FROM table_8489 WHERE "Away team score" = '16.9 (105)'
What's the crowd size with an away score of 16.9 (105)?
CREATE TABLE table_8489 (
    "Home team" text,
    "Home team score" text,
    "Away team" text,
    "Away team score" text,
    "Ground" text,
    "Date" text,
    "Crowd" real
)