old school => 600 API => 5% of students score proficient or advanced on state tests
new school => 800 API => 60-75% of students score proficient or advanced on state tests.
I was asked during the interview how I handled a student who didn't do their homework. I laughed and said, "If a student in my current school does homework then I get excited and give them a high five."
API is a state ranking based on a total possible 1000 and built around test scores, high school exit exam pass rates, graduation rates, etc.
In a 'general manner' ... Proficient means the kid scored above 60% on a state test