His P85 version of the Model S already has over 188,000 km (117,000 miles) on the odometer, but the battery pack was replaced at 86,000 km due to some problem with power switching (not related to batteries itself, according to Nyland).
That means that this test concerns battery degradation only for the last ~100,000 km (over 60,000 miles) and about one year.
The result of the range test at full charge is about a 4% capacity drop compared to his car when new, but remember that this is just user estimation.
"I test and find out that there's approx 4 % degradation after one year and 100k km/60k mi. That's not too bad considering that I drive 4-5 times more than most pepole. If the annual driving distance is 20-25k km, I assume that even after 8-10 years, the capacity should still be over 80 %."