When I bought our LEAF second hand in Jan 2017 it showed 64 Ahr battery capacity. This was almost certainly a reset and within 6 months the battery had settled down to ~ 90% SOH. The next 18 months the car lived in Colorado and since then it has lived in Albuquerque. Needless to say, Albuquerque is warmer. In ~ July of this year the car lost its 12th capacity bar when SOH was ~ 84%.
Regarding the data: For the most part I grab LeafSpy data about once a month and plop it into a spreadsheet. The following graph is that data.
Ignoring the gyrations through the seasons I seem to be losing ~ 0.5 kWh of capacity (about 2 miles of our type of driving range) a year. We are still able to use the car for our purposes by charging to 80% SoC so in effect we have a good 20% SoC buffer to rely on in the future when serious battery range loss has occurred. So far, no drama with the car and I remain somewhat optimistic that the car will give us another 5 years of service. Maintenance costs to date include wiper blade inserts and new tyres followed by an alignment. The OEM set had worn asymmetrically on the outsides.