Around 2010, it was possible to recycle non-ferrous metals equivalent to 30% of an airplane's weight. Several published reports mentioned recycling 80% of everything that could be recovered from an aircraft. It's extremely variable.
But the new generation of aircraft are made with an enormous amount of composite materials, which are more difficult to recycle than aluminum. The amount you can recover is rather variable. That opens the door to research and development work to find ways of recycling these materials and giving them a second life, on the one hand, and on the other, to look into what can be done with these materials and find places they could be used elsewhere.