You might be surprised. I used Leaf Spy on maybe 6 or 7 different cars, all 2013 or 2014 between 19k and 48k miles and the results were all over the place. I bought the best battery I found, and it just happened to have the perfect options package for me
Anyway what I saw was interesting, on the low end the 19k mile '13 SL had 54Ah, it showed 12/12 bars but either was about to drop or had been reset. I also saw a 48k mile '13 S that measured 57Ah, that was the highest mileage car I drove. I saw a '13 SV with about 29k and it was 51Ah, it also showed 12 bars so I'm guessing had been reset. The '13 I bought showed 61.8Ah and it has now climbed to 64Ah, it has 29k miles. Interestingly (or maybe it's obvious) the cars I saw that were in the worst shape with worn interior, scuffed rims, dinged and dented paint, etc had worse battery than well-maintained cars. Huh, imagine that!