I ended up losing nearly 15 years of my Google Location history during the switch to on-device, so if you're interested in doing analyses like this, be sure to back up your data on Takeout before you enable the on-device setting that nemo1618 mentioned. Once that setting is set, the data is no longer available on Takeout, and if the data didn't fully transfer to your device, which is what happened to me and to some others, it's gone: https://www.reddit.com/r/GoogleMaps/comments/1diivt3/megathr...