The easiest way to view download statistics for a PPA package published on Launchpad.
It's a little confusing to see stats listed for s390x packages when no such build was ever made. I suspect this is a simple display error, probably defaulting to "s390x" instead of "all" for architecture-agnostic packages.
This issue appears to be discussing a feature request or bug report related to the repository. Based on the content, it seems to be still under discussion. The issue was opened by foresto and has received 4 comments.