I'm trying to calculate a field based off another field each time a new feature is created or when the field being calculated from is changed. For example, I have a sewer cleaning line feature class with a "Date Cleaned" field and a "Years Since Cleaned" field. I want the "Years Since Cleaned" field to auto populate with the number of years, today's date minus "Date Cleaned" field to give me a number, or automatically change when the "Date Cleaned" field's data is modified or new data is added.