user: ### NOW ANSWER:
Question: Which Week has an Opponent of baltimore colts, and an Attendance smaller than 55137?
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Game site', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'text', 'real']
Sample row: [1.0, '1975-09-21', 'at Buffalo Bills', 'L 42–14', 'Rich Stadium', 77837.0]
SQL:

assistant: SELECT AVG("Week") FROM "Table" WHERE "Opponent" = 'baltimore colts' AND "Attendance" < 55137.0;