We build retrospective series for the Human Assets Index from the United Nations—Committee for Development Policy data. The HAI is a composite index which includes health and education components. Our series cover 145 developing countries for the period 1990–2014. The analysis provides insights into the changes in the HAI and its distribution for different groups of Developing Countries. We discuss the importance of the HAI’s components by considering the weight given to them in the index. We propose a new weighting scheme which is optimized based on the correlation ratio and linearity (nonlinearity) relationship between components, and we present the country ranking changes due to the optimized HAI.