Well, it’s worth remembering that the Rotten Tomatoes Tomatometer rating is simply the percentage of critics who liked the movie, not an average of those critics’ scores. A passably entertaining movie can easily get high scores if it doesn’t have any glaring flaws that cause critics to dislike it. In theory, a movie could get 100% on RT if all its critics individually rate it as 6/10 because a 60% review would still be considered “positive” in the Tomatometer’s eyes.
On the other hand, if you look at the movie’s “Average Rating” instead of its Tomatometer score, it only got a 8.2/10.
Essentially, this means that 92% of critics liked the movie overall, but their average score meant they thought it was merely good, not great.
Competing site Metacritic uses an average score system as well. City of God got a 79% there.