To be placed on the NWL you must have a nomination and be 3Qd (fully qualified in every way) by West Point. However, the NWL can have approximately 1,700 names. This number could be a couple hundred more or less each year. They are rank-ordered by West Point #1 through last. Usually about 400 or so people (again could be between 300 and 500 in a given year) are offered appointments from this list. Unfortunately, there are several hundred more fully qualified people with Nominations each year than there are slots.
The only thing you can do is to work hard to improve your position on the NWL. Your Regional Admissions Officer will probably not tell you exactly where you are on the list but they can tell you how to improve your position (get Boy's State, leadership position in school, better SAT/ACT scores etc). Do not just stand-by and see what happens - make yourself more competitive.