user: Question: Name the average week for result of L 28–17
Columns: ['Week', 'Date', 'Opponent', 'Result', 'Game site', 'Attendance']
Types: ['real', 'text', 'text', 'text', 'text', 'real']
Sample row: [1.0, '1984-09-02', 'at Indianapolis Colts', 'W 23–14', 'Hoosier Dome', 61148.0]
SQL:

assistant: SELECT AVG("Week") FROM "Table" WHERE "Result" = 'L 28–17';