these countries face a double challenge they must expand secondary education while also ensuring that students who complete compulsory education are at least able to read and understand texts and to use numbers at a level that enables them to further develop their potential and participate in knowledgebased societies for instance between and the population of yearolds enrolled in grade or above increased by almost students in brazil by more than students in turkey and by more than students in mexico reflecting the increasing capacity of these countries to retain young people in school these improvements are also evident in improved coverage rates of the national populations of yearolds enrolled and not enrolled in pisa samples countries showing positive coverage trends also include costa rica indonesia and uruguay