Human Development Index(HDI) is NOT the most reliable measure to assess human development as it does not say anything about ?

Distribution of human development

The human development index (HDI) ranks the countries based on their performance in the key areas of health, education and access to resources.. The human development index measures attainments in human development. It reflects what has been achieved in the key areas of human development. Yet it is not the most reliable measure. This is because it does not say anything about the distribution.