“If IAG were to acquire Norwegian and its 3% share of seats in Europe, this would just take the expanded IAG to the top of the European ranking by seats, with a share of 12% (to be more precise, it would be 12.24% – very slightly ahead of Lufthansa Group's 12.17%).”
Some statistics and facts like the one above I’ve copied out are what you need. The article is full of them. Forget about the America comparison. Just read some stats. Very interesting in my opinion especially after reading lots of miss information above. Norwegian is tiny.