Active users credits problem

Hi guys, recently our team has been doing some research on circleci credits. But I’ve found something that makes me confused

So, the number of active users varies a little in some months, but their final credits differ too much :face_with_raised_eyebrow:

As you can see in Aug we got 56 active users and it came out to 1,400,000 credits
But in Jun, we got 53 active users with 0 credits

We are curious about why this happens. Why are the total credits so different?

Thank you very much if you can answer this question for me :grinning: