| Nigrescence |
Actually, I would say that the lower end of the number range given for medium and heavy loads is a formality. If your light load is 33, anything past that is medium load. If your max load is 100, you can't hold more than 100 as a heavy load.
Whatever the case, the absolutely important thing to remember is that your light load limit is 33, and your maximum heavy load limit is 100.
I would say that you're past your medium load limit. You're into heavy.