Again, this is bike shedding bait. I'm going by my own experience with basic mathematics in my American education where "percent" is something you multiply a number by, and usually ranges from 0 to 1.

Ex. 50% of 12 marbles is 6 (*.5, 50%).

But just looking at all the different answers in the comments here means there's no consensus on a "right" way. Hence bike shedding. A decent code base should be consistent so it can focus on more important things.