Tracking progress on fields in uploaded data

Every month, we receive a simple excel file with student data. The file has key fields (immunization, attendance, fees etc) with a status (compliant, non-compliant, waived) for each student. Every month, we upload this data in a table called Student Progress, in which every student gets a new record showing the most recent status on each of the key fields. Each month we notify a caseworker with a list of fields that are non-compliant (the table is a child of the Student Profile table).

However, we'd like to notify the caseworker only if the status changes from compliant or waived to non-compliant. That is, if the status is non-compliant this month and is still non-compliant next month, we don't want to notify the caseworker again. 

My hope was to find a way to create a field that, upon upload, checks, say, if immunization status from last month is not equal to immunization the status this month and if this month's status is non-compliant. If the check is positive, then use the field to send notification to caseworker.

Please help.