user: Question: what is the manner of departure when the date of vacancy is 15 September 2008?
Columns: ['Team', 'Outgoing manager', 'Manner of departure', 'Date of vacancy', 'Replaced by', 'Date of appointment', 'Position in table']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Bournemouth', 'Kevin Bond', 'Contract terminated', '1 September 2008', 'Jimmy Quinn', '2 September 2008', '23rd']
SQL:

assistant: SELECT "Manner of departure" FROM "Table" WHERE "Date of vacancy" = '15 September 2008';