Answer:
Differences in life expectancy and education indexes, as well as differences on national income per capita.
Step-by-step explanation:
The Human Development Index is a composite index aimed to measure people's quality of life accross countries based not only on economic growth, but taking into account other key dimensions of human development. HDI offers a more complete analysis than those based solely on GDP.
HDI is the geometric mean of normalized indices of three dimensions: 1) health (measured by life expectancy at birth), 2) education (measured by mean of years of schoooling for adults) and 3) standard of living (measured by gross national income per capita)