Timed Average of a single data point on Distech GFX.

Hello everyone. I was wondering if anyone has had any luck creating logic that averages a single points value over the course of an adjustable amount of time.

We have an airflow station that the engineer wants me to calculate the rolling average over a 5-15 minute window and spit out that value but I'm not sure how I can store that data in memory to be used in the future.