The primary source of global data on out of school children is the Education for All Global Monitoring Report. The 2007 Global Monitoring Report (GMR), launched on 26 October 2006, estimates that there are around 77 million primary-aged children who are not enrolled in primary or secondary school. The GMR helps track progress on the Universal Primary Education Millennium Development Goal to ensure that by 2015 children everywhere, boys and girls alike, will be able to complete a full course of primary schooling.
Given its emphasis on the enrolment statistics of primary-aged children, the GMR does not make a comparable estimate of secondary-aged children out of school. It does, however, estimate a global net enrolment ratio in secondary education of 58 per cent. Net enrolment ratio is enrolment of the official age group for a given level of education, expressed as a percentage of the population in that age group.