A school is planning to form a school council. The council will consist of 4 groups of student from years?

9, 10, 11, 12 respectively. Each group will comprise not less than two students from the same year and the total number of students i nthe council is to be nine. In how many ways can the school council be formed, if there are three, four, five and six candidates from years 9, 10, 11 and 12 respectively.