Kiril Simeonovski, 07/06/19 09:57:
with their contributions to the Wikimedia projects
Do you mean the *number* of their contributions, or literally all their contributions? Filtering the stub dumps would be one systematic way to get all the metadata about edits.
If you just need aggregate numbers with some filter by date, namespace or other, the fastest way is probably to write a script which loops through all the databases on Labs. For instance I made this to list the users who contribute in a certain language, to find translators for very small languages: https://gerrit.wikimedia.org/r/plugins/gitiles/labs/tools/lists/+/master/scripts/userslang.py
Federico