91/95 expressed as a percentage is 95.79%. This number tells you how close the fraction is to a whole when you look at it in everyday terms.
Being just a little under 100% means the fraction is very large—almost the entire amount. In real life, you might see a similar value when something is almost finished or when a score is near perfect.
Whenever you need a quick sense of size, turning 91/95 into 95.79% makes it easy to compare with other percentages, like test scores or discount rates.