High school education, students take four years to finish elementary education before most students who study high school will have a 12-year-old, and studied at the age of 15 years.
Secondary education students must take four years of graduate school at the end of first grade, most students who study will last 12 years and graduated at the age of 15 years.
Secondary education take four years by the students must graduate primary school students before the students mainly study will last 12 years and graduated at the age of 15 years.