\ Global Youth Development Index and Report 2016 Figure 2.5  Biggest risers and fallers globally between 2010 and 2015 Improvement 25% 20% 15% 10% 5% 0 -5% -10% Deterioration 32 -15% -20% Kenya South Africa Niger Togo Malawi Chad Algeria Haiti Angola Pakistan Source: Commonwealth Secretariat Between 2010 and 2015, average YDI scores for all the regions improved. However, there were larger changes in the average scores for some regions than for others (Figure 2.4). Since 2010, eight countries have moved up from the low to medium YDI category and three countries have fallen from the medium into the low YDI category, resulting in a 26 per cent net decrease in the proportion of young people living in low YDI countries (see Table 2.2). Similarly, 11 countries have progressed out of the high YDI into very high YDI category, and one country has fallen from the very high YDI to high YDI category, leading to a 16 per cent net increase in the proportion of young people living in very high YDI countries. Figures 2.5 and 2.6 show how the YDI rankings have changed between 2010 and 2015. These improvements indicate that more young people have decent prospects today than in 2010. In general, youth development has improved consistently from 2010 to 2015. Eight countries moved up from the low YDI category over this period, while Pakistan, Angola and Haiti went in the other direction from medium to low YDI category. Box 2.1 Definition of YDI categories The YDI score is a number between 0 and 1. A score of 1 would represent the highest level of youth development attainable for a country, while a score of 0 would indicate the lowest possible level of youth development. Using these scores, countries have been grouped into Very high, High, Medium and Low categories or levels of youth development in the YDI. This categorisation reflects the position of a country on a spectrum ranging from ‘relatively good’ to ‘relatively poor’. The scoring system is the same as the one that underpins the HDI. The YDI categories by score are: Low 0–0.494 Medium >0.494–0.607 High >0.607–0.671 Very high >0.671–1