At my high school (private, Canadian) and all the Canadian universities I've attended, 80%+ was an A.

In my high school graduating class of ~100, only the top 5 students had averages above 90.

To be in the top 1% of the faculty of arts and science as a whole in my undergrad didn't require a 90%+ average. The lower cut-off was around 85% for top 1%, depending on the year.

In the grad schools I attended, a 3.7 GPA (A-) was the approximate minimum threshold for the top 10% of the program.

What is to give light must endure burning.