[Pre-BB] MapleStory Formula Compilation

I'm not quite getting the energy charge growth formula:

Energy Charge:
10000 units = 1 fully charged meter
Charge rate: Skill % * 100 units per monster per hit. In other words, at maximum level, it charges 192 units per monster per hit.
Energy Charge decay: 200 units / 10 seconds while inactive

What's the "Skill %"? How do you turn 40 into 1.92? Or is there some hidden "Skill %" for each level of Energy Charge, but just isn't stated in-game?