I'd rather see that breakdown by years not months.
So would I. The problem is just that just very few players keep their pilot ID over such a long period like 10 years.
Edit:
I just gave it a quick shot: I took all pilot ID's of tour 148 that have played every tour in the year before
and have been present in tour 70 as well. I came up with just over 500 pilots. Now I can't really tell if they are exactly the same
players, but while browsing through the list I reckognized the majority as well known longtime players.
And within this group, the median was as follows: K/D 0.96, K/S 0.57, K/H 3.1 and Hit% 4.42. (This would support one theory of mine that by and large the learning curve ends after about 12-18 months for most players.)
But the database for this is a bit shakey in my opinion.