Joelcool - I have a link that can disprove it for you.
Total NES games shipped = 500.01 million. 20% of that is 100 million.
So I need to find 101 million 1st party sales
SMB1+2+3 = 40.23+18+10 = 68.23
Good start
Zelda I/II = 10.89
Data above is from http://en.wikipedia.org/wiki/List_of_best-selling_video_games#Nintendo_Entertainment_System, which took the data from retailer shipment figures
Data below from VGChartz
DuckHunt = 24.53 million
Total from 6 Nintendo games = 103.65 million = 20.61% of all NES games sold







