UNDP
Since 1990, the UNDP publishes the annual Human Development Index (HDI). This is used as a global indicator of wealth and shows ‘differences in development.’ The Index is made up of various dimensions of human development: life expectancy, years of schooling and further education, education index and the gross national income. According to their index value, countries are assigned to one of the four classes: Very highly developed countries, highly developed countries, countries with medium human development, and countries with low human development.