The gross enrollment ratio (GER) or gross enrollment index (GEI) is a statistical measure used in the education sector to determine the number of students enrolled in school. It is expressed as a percentage of the population in the official age group corresponding to a specific level of education. The GER can be over 100% because it includes students who may be older or younger than the official age group, such as those who are repeating a grade, those who enrolled late and are older than their classmates, or those who have advanced quickly and are younger than their classmates. A high GER generally indicates a high degree of participation, whether the pupils belong to the official age group or not. However, a high GER may also reflect a substantial number of overage children enrolled in each grade because of repetition or late entry rather than a successful education system. The net enrollment rate excludes overage and underage students and more accurately captures the systems coverage and internal efficiency.