Mexican Education and Schools?

I am arriving tomorrow and am in need of information about the school systems there! What is the age of students? What are the different grade levels? Why the two seperate times for classes? What are the requirements for students to have to complete? Like here in the U.S. they must be at least 16 before they can say that they do not want to go any longer. What grade level is considered completed when the student graduates? I will be doing a presentation on this subject for my college work, so all the information I can get is greatly appreicated!

Thanks, Missy

The schools here are the same as in the States and Canada. You can leave at 15 but have to stay until 18 to graduate. The reason for the 2 class times, (morning class starts at 7:00am and finishes at 2:00pm, afternoon class starts at 2:00pm until 7:00pm) is because there are too many children for one time. Also, they tend to put the slackers in the afternoon class. They wear uniforms also.