question: What is the date of vacancy for 10 december 2007 when quit?
answer: SELECT date_of_vacancy FROM table_11713303_2 WHERE date_of_appointment = "10 December 2007" AND manner_of_departure = "Quit"
context: CREATE TABLE table_11713303_2 (date_of_vacancy VARCHAR, date_of_appointment VARCHAR, manner_of_departure VARCHAR)