Percentage of students at the lowest level of science proficiency is the percentage of students at the lowest level of proficiency on the science scale in national or international assessments

Percentage of students at the lowest level of mathematics proficiency is the percentage of students at the lowest level of proficiency on the mathematics scale in national or international assessments

Percentage of students at the lowest level of reading proficiency is the percentage of students at the lowest level of proficiency on the reading scale in national or international assessments

Mean performance on the mathematics scale is the mean mathematics score for students in national or international assessments

Mean performance on the science scale is the mean science score for students in national or international assessments

Mean performance on the reading scale is the mean reading score for students in national or international assessments

Percentage of population aged 15 years and over who can, with understanding, both read and write, a short simple statement on his / her everyday life. Generally, ‘literacy’ also encompasses ‘numeracy’, the ability to make simple arithmetic calculations (Source: UIS: p.3)