Segments Expire? How to track lifetime statistics?

One thing I was hoping to use unity analytics for was to track lifetime statistics of my application. I created segments to track the information I wanted, but noticed now after a few months after release that these statistics (such has installs per platform) are decreasing. The documentation doesn't mention any time limits to data collected by segments, but given the default "all current users" segment says it tracks only 90 days and has no custom rule for it, I'm guessing segments actually only track the last 90 days. If that's true, that means that the data I want from our launch is gone, and I have no way of looking it up other than parsing the raw data myself.

So the question is, if segments are expiring, how do I use analytics to track lifetime statistics? Am I forced to download the log of events and do all of the processing manually? That would involve generating dumps and downloading each and every day's data since launch. That wouldn't be a huge deal, but there's also no way to download more than a single days data at a time, you have to download each individual days data separately (and more than once if you want custom and login data, for example)... a huge and tedious process. This feels like a bit of an oversight.