Lower secondary completion rate, total, national source (% of relevant age group)
Under certain circumstances, the computation can under- or overestimate the actual proportion of a given cohort completing lower secondary school and sometimes exceeds 100% due to over-aged and under-aged children who enter lower secondary school late/early and/or repeat grades, or due to the use of a population denominator that is derived from population projections or interpolations, which may under- or over-estimate the real population size. The data derived from national sources may differ from international sources because of divergences in definitions, methods of calculation, or in some cases due to different underlying data.  For these reasons, the data based on national sources in this database should not be used for making comparisons between countries, but rather for assessing the progress of individual countries.
The lower secondary school completion rate is the percentage of children who are completing the last year of lower secondary education. It is computed by dividing the total number of students in the last grade of lower secondary education school minus repeaters in that grade divided by the total number of children of official completing age. Country-specific definition, method and targets are determined by countries themselves.