What is the number of students in secondary schools us everyyear?

There's no single, readily available number for the total number of students in US secondary schools every year. The number fluctuates slightly year to year and the definition of "secondary school" (middle school vs. high school, grades included) can vary depending on the source.

To find the most up-to-date information, you should consult the National Center for Education Statistics (NCES). Their website (nces.ed.gov) contains detailed data on enrollment in public and private schools at all levels, including secondary education. You'll likely need to navigate their data tools to find the specific information you need, possibly aggregating data across different grade levels depending on your definition of "secondary school."