CBS (Dutch bureau of statistics) has a very high reputation when it comes to fact sheets.
They published their report on NOx contribution by the various sectors of transportation.
Regarding Air traffic, they ONLY CONSIDER TAXI, START AND LANDING.
Now consider these two screenshots I took (06-oct-2019 10:32) from Plane Finder, and draw only one conclusion: TRUE OR FALSE?
Air traffic < 3000ft to and from Schiphol: