Jefferson County International Baccalaureate (JCIB) School in Irondale ranked as the No. 12 most challenging in the nation,  according to the Washington Post. The study took the number of college-level tests given at the school last year and divided it by the number of graduates that year, which gave the school an index score of 11.214.

Here are a few other facts about Jefferson County IB that factored into the study:

• The school moved up 6 spots this year from last year’s list.

• Jefferson County IB previously has ranked as highly as the No. 2 most challenging high school (in 2010.)

• The school’s four-year graduation rate is 100 percent. Enrollment is 365 students.

American Indian Public Charter in Oakland, Calif., ranked as the No. 1 toughest high school, with an index score of 21.909.

Other schools in the Birmingham area ranked on the list of 1,900 schools include Mountain Brook High School (No. 462), Oak Mountain High School (No. 559) and Homewood High School (No. 825).

Click here for full story by Brent Godwin of The Birmingham Business Journal