This page might help explain why:
"To make sure we're getting a fair picture, we'll adjust how far we look back (the "evaluation period") depending on how much you've sold recently:
- If you had more than 400 transactions in the past 3 months, we'll count all those transactions
- If you had fewer than 400 transactions in the past 3 months, we'll count all your transactions from the last 12 months"
Have you had fewer than 400 transactions in the last 3 months?
Give me ambiguity or give me something else.