What is “70% nitrogen in air”? https://en.wikipedia.org/wiki/Atmosphere_of_Earth https://en.wikipedia.org/wiki/Atmosphere_of_Earth: “As of 2023, by mole fract

What is “70% nitrogen in air”? https://en.wikipedia.org/wiki/Atmosphere_of_Earth https://en.wikipedia.org/wiki/Atmosphere_of_Earth: “As of 2023, by mole fraction (i.e., by number of molecules), dry air contains 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases.” Did they take out nitrogen, added 7 parts nitrogen to 10 parts of air, use something else than mole fraction, …?