Absence Helper by Percentage

Would love to have absence helper with a percentage of classes missed. Take the total classes a student is enrolled in for a semester (or year) and once they have passed that threshold, an email is sent. Still offer capability for different second email at a higher percentage threshold.

Reason being that some of our students take 1 class a week and some take 13 so class counts dont work. Our attendance policy is that you are only allowed to miss 25% of classes per semester before disciplinary action is taken.