Speaking of Navs, and I am talking of those that already jumped the AFCO, OASC, and IOT hurdles, 30% or more still wash out.
Many who washed out we're chopped pilots but that was when pilot intakes were much higher. Now I would expect competition would be stiffer so standards higher.
However there is one interesting change. This thread on Pprune used to be very active with potential applicants; now interest is close to nil.