It has been posted before, but it seems it needs to be posted again:
From that article:
“Because there’s a company called comScore that provides exit poll surveys that, while it is an opt in survey, is one that adjusts to reflect the movie going population. […] comScore surveys almost a thousand audience members in 20 markets immediately after they view the film, including The Last Jedi. […] this data shows the audience liked The Last Jedi a great deal. Rating a movie as either “excellent” or “very good” tends to be the key metric in most Hollywood evaluation of content, both in testing and in exit polls. Anything over a score of 80 in the “top two boxes” is concerned a great score, and The Last Jedi has a top two box score of 89.”