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 (admittedly limited) 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.
Later battery updates are down-thread