To me the most interesting thing is that most of those downloads have happened within the last 12 months. Almost a third of them have happened in the last 90 days. Tzdata has been on hex as its own package for about 1700 days by the time of writing. Almost 30% of all of the downloads happened in the most recent 5% of the time the package has been available.
Looking at other packages the numbers look similar in that they are downloaded more often than a year ago.
What does a download mean?
From my own experience a lot of downloads happen from running automated tests on Continuous Integration systems. When you run a test, this can trigger multiple downloads of a package that is a dependency.
If one project has a certain hex package as a dependency, that can easily cause hundreds or thousands of downloads over one year.
On its own the number does not mean that much. But looking at the development of the numbers over time I think it can be used as a non-scientific proxy for how much a package is used. And since the trend seem to be similar across various often-downloaded packages also a proxy for use of the Elixir language. This would suggest that Elixir is getting used more.