Did the HDI rankings change for many countries in 2017?

In general, the rankings change a little between two successive years because of the nature of the HDI component indicators. With the exception of gross national income per capita, other indicators change very slowly year to year.
Based on the consistent data series that were available on the cut-off date for downloading data for the computation of composite indices for the 2017 Statistical update, there are several countries with ranks that changed between 2016 and 2017. The HDI values for 2016 and 2017 are given in Table 2 of Statistical Annex, the corresponding ranks are given in Table1. In Table 2 we also provide the change in ranks between 2012 and 2017.
The consistent data are based on the latest updates and data revisions and are obtained using the same methodology. The effect of change in achievements (improvement or decline) in human development indicators in terms of health, education and living standards is captured by comparing the HDIs obtained from such a consistent data series.
The difference between HDI values (and ranks) published in HDRs for different years represents a combined effect of data revision, change in methodology, and the real change in achievements in indicators.
We advise users of the HDI not to compare the estimates from Reports published in different years, but to use the consistent data given in Table 2 of the latest report or to use data series available in the on-line database http://hdr.undp.org/en/data.