Whenever you need to know the percentage of another number from 100 the percentage is always that number. I don't know if I explained that very well but if I didn't here are some examples.
Ex: 15 of 100 is 15%
Ex. 75 of 100 is 75%
Ex. 99 of 100 is 99%
Ex. 52 of 100 is 52%
Ex. 10 0f 100 is 10%
I really hope this helps i tried my best to explain, have a great day!!!