Labor force by education attainment provides insights into skill levels of labor force (employed and unemployed) and may be used to draw inferences about changes in employment demand and education policy.
Labor force with secondary education (% of total)
Data on the labor force are compiled by the International Labour Organization (ILO) from labor force surveys, censuses, establishment censuses and surveys, and administrative records such as employment exchange registers and unemployment insurance schemes. For some countries a combination of these sources is used. 

Labor force surveys are the most comprehensive source for internationally comparable labor force data. They can cover all non-institutionalized civilians, all branches and sectors of the economy, and all categories of workers, including people holding multiple jobs. By contrast, labor force data from population censuses are often based on a limited number of questions on the economic characteristics of individuals, with little scope to probe. The resulting data often differ from labor force survey data and vary considerably by country, depending on the census scope and coverage. Establishment censuses and surveys provide data only on the employed population, not unemployed workers, workers in small establishments, or workers in the informal sector. 

The reference period of a census or survey is another important source of differences: in some countries data refer to people's status on the day of the census or survey or during a specific period before the inquiry date, while in others data are recorded without reference to any period. In developing countries, where the household is often the basic unit of production and all members contribute to output, but some at low intensity or irregularly, the estimated labor force may be much smaller than the numbers actually working. 

Besides the limitations to comparability raised for measuring labor force, the different ways of classifying the education level may also cause inconsistency across countries. Still, information on educational attainment is the best available indicator of skill levels of the labor force to date.
Labor force with secondary education is the share of the total labor force that attained or completed secondary education as the highest level of education.
Labor force with secondary education is calculated by dividing the number of labor force who attained or completed secondary education as the highest level by the total number of labor force, and multiplying by 100. 

The labor force is the supply of labor available for producing goods and services in an economy. It includes people who are currently employed and people who are unemployed but seeking work as well as first-time job-seekers. Not everyone who works is included, however. Unpaid workers, family workers, and students are often omitted, and some countries do not count members of the armed forces. Labor force size tends to vary during the year as seasonal workers enter and leave. Usually active population is measured in relation to a long reference period such as a year, and the currently active population (labor force) is measured in relation to a short reference period such as one day or one week.

The levels of educational attainment is based on the International Standard Classification of Education (ISCED), which was designed by the United Nations Educational, Scientific and Cultural Organization (UNESCO) to ensure the comparability of education programs at the international level. Note that primary education refers to ISCED 1 (primary) and 2 (lower secondary), and secondary education consists of ISCED 3 (upper secondary) and 4 (post-secondary) here.