It's been over a year since my Norfolk pine put on new branches. Other wise it looks fine. What seems to be the problem.
Unfortunately it is difficult to replicate the growing conditions that Norfolk Island prefer. Good sunlight and high humidity.
Incorrect watering, too much or too little can also result in excessive needle and branch dropping.
This is a very old specimen and even though the overall height of the plant is still appropriate to your home, many times these plants outgrown the home environment.
Pruning is not an option with Norfolk Island Pine, topping the plant will just give you a plant with no top.
It really is best to start over with a new plant.