The Human Development Index (HDI) is a composite statistic used to rank countries by level of "human development" according to three dimensions: health, education, and living standards. It provides a frame of reference for both social and economic development of a country, ranging from 0 (zero development) to 1 (highest level of development). Out of the countries found within the Himalaya Hindu Kush region, China ranks the highest (101st), Afghanistan the lowest (172nd). A total of 187 countries are surveyed.