another datapoint. I've seen my range appear as varying numbers over the last 27 month.
Started out in 05/2018 with 309 which slowly rose to 311
By 10/2019 and 26k miles it was 308
Then saw a bunch of range drops
11/2019 it was down 298 still 26k miles
12/2019 with 27k miles it was 290 mile
02/2020 with 30k it was at its all time low of 286 miles
then it started creeping back up again
By 03/2020 it was back to 291
05/2020 it was 295 before falling back to 291 in 06/2020
now, in 08/2020 with 35k miles it has crept back up to 302
Which gives me less than 3% loss depending on which starting number you use.
Its been interesting tracking it, but tells me "degradation" is definitely not the correct word to use
[edit]
From TeslaFi
860 charges which collectively added 8,500 kWh