I had already tweaked my Recorder storage from the default of 10 days to 30, but was looking to view statistics for longer (e.g. a year). Maybe this is common knowledge, but I've use HA quite a while, and today I learned that many integrations have sensors that are already setup to store long term statistics for an indefinite amount of time.
Confusingly, these stats aren't shown anywhere in the default UI (as far as I can tell). Whether you go to the Entity properties, or the History page, neither shows these long term stats (just the shorter, Recorder ones). The only out-of-the-box way to view them seems to be with the "statistics graph" card.
To make it easier to view this useful info, stumbled on this awesome custom UI card. It let's you swap out the default "history" graph on Entity properties, with one that will automatically pull from "long term statistics" when you zoom out - https://github.com/alexarch21/history-explorer-card#overriding-the-ha-more-info-history
One thing to note is, setting this is all client-side, so you'll need to select the override option in each browser / mobile-app you use. Works great!
Hope this helps someone!
Great! Yeah it seems like very useful information, hopefully HA will make it more accessible / obvious to access in the future!