The United Nations publishes a Human Development Index (HDI) every year, which consists of the Life Expectancy Index, Education index, and Income index. The Education Index is calculated from the Mean years of schooling index and the Expected years of schooling index.Education is a major component of well-being and is used in the measure of economic development and quality of life, which is a key factor determining whether a country is a developed, developing, or underdeveloped nation.