I want to count each user’s monthly statistics

The statistical information here is cumulative. How to change it to monthly?

You can view stats by different time periods by using the User Directory if you have it enabled (/u). You can also use the wrench on that page to add/remove columns.

Here’s ours - https://meta.discourse.org/u

Though if that’s not specific enough, you can use the data explorer to create something more tailored.