Originally Posted by ///M Rakete
I would say that is a fair assessment. A track day might be worth 500 miles of average driving. Let's take your case, 14 track days, say that's equivalent to 7,000 miles plus the 6,800 makes 13,800 miles. Close enough to a nominal 15k. I'm not going to say that the 1 track day to 500 miles ratio always applies but it isn't unreasonable in my book.
Interesting thought and you most likely are right with the 1 track day 500miles conversion. The question is should we apply that not just for the oil change but for other maintenance interval as well.
During my track days I am on the track about 80-100 miles so there is x5 factor for wear and tear compared to normal driving.