Calculate/count # of consecutive years of employment by status

[MADDPM]

I work with contracts spanning academic years. I need to create a report that shows consecutive years of service in part-time or full-time status. For example a temporary employee may work:
2009-10 – Full time
2008-09 – Full time
2007-08 – Full time
2006-07 – Part time
2005-06 – Part time
2004-05 – Full time

I would like the report to list each academic year in descending order, then group by full time or part time and produce a total count of the academic years in the status category. I have not been able to successfully do this with the Access report sorting and grouping feature.

For example:
2009-10 – Full time (count = 3 consecutive years)
2008-09
2007-08
2006-07 – Part time (count = 2 consecutive years)
2005-06
2004-05 – Full time (count = 1 consecutive years)

The report is based on a query using the tables/fields below (I only listed the most-relevant information):
TABLE: EMPLOYEE
Relevant FIELD: [EMPLOYEE_Number]

TABLE: APPOINTMENT
Relevant FIELDs:
[Employee_Number]
[APPOINTMENT_ID]
[Begin_Date]
[Expire_Date]
[FT_PT]

TABLE: CONTRACT
Relevant FIELDs:
[Appointment_ID]
[Contract_AY]

Can anyone help?

(using: Access 2007, Windows XP)

Thanks in advance-
Colleen