Taking the grade as the unit, a school divides the students' academic performance into four grades: excellent, good, medium and poor  In a school year, the top 10% of the total score of each examination is excellent; The last 30% is poor, and the rest is good and medium
In the last academic year, there were more excellent students in grade 12 than in grade 11
There are more students with poor grades in grade 12 than in grade 11