The Human Development Index is published annually by the United Nations Development Programme (UNDP) in its Human Development Report.

The HDI is a composite index that measures a country's achievements in three basic dimensions of human development: health (measured by life expectancy), education (measured by mean years of schooling and expected years of schooling), and income (measured by gross national income per capita).

Norway has consistently ranked highest in the HDI since 2009, due to its high scores in all three dimensions of the index: health, education, and income.

Niger has consistently ranked lowest in the HDI since 2009, due to its low scores in all three dimensions of the index: health, education, and income.

The HDI is calculated using the following formula: $HDI = \frac{1}{3} \left( LI + EI + HI \right)$, where LI is the Life Expectancy Index, EI is the Education Index, and HI is the Income Index.

The maximum possible value of the HDI is 1.0, which represents the highest possible level of human development in all three dimensions: health, education, and income.

The minimum possible value of the HDI is 0.0, which represents the lowest possible level of human development in all three dimensions: health, education, and income.

Mauritius has the highest HDI in Africa, due to its high scores in all three dimensions of the index: health, education, and income.

Singapore has the highest HDI in Asia, due to its high scores in all three dimensions of the index: health, education, and income.

Chile has the highest HDI in Latin America and the Caribbean, due to its high scores in all three dimensions of the index: health, education, and income.

The United Arab Emirates has the highest HDI in the Middle East and North Africa, due to its high scores in all three dimensions of the index: health, education, and income.

Estonia has the highest HDI in Eastern Europe and Central Asia, due to its high scores in all three dimensions of the index: health, education, and income.

Mauritius has the highest HDI in Sub-Saharan Africa, due to its high scores in all three dimensions of the index: health, education, and income.

Barbados has the highest HDI in the Caribbean, due to its high scores in all three dimensions of the index: health, education, and income.

Australia has the highest HDI in the Pacific, due to its high scores in all three dimensions of the index: health, education, and income.