Adobe Acrobat Customer Javascript

I am trying to create a custom JavaScript but literally have no idea what I am doing. 

I created a custom evaluation scorecard with 15 opportunities for points. Various sections may be N/A. My dropdowns are named "Dropdown1" through 15. My total is "Total" - Each time I calculate it with the presets Acrobat provides, it gives me 6,000.00%, but I need this ONLY to show 60%. Each dropdown has the option to get 0%, 50%, 100%, or N/A. Can someone help me with a custom JavaScript to correct this issue?