\ Global Youth Development Index and Report 2016 145 −6% Medium 408 454 11% High 15 1 −94% Very high 26 41 58% Very High 13 154 YDI levels in 2015 High 9 Low YDI levels in 2010 Medium 15 Percen­ tage change Low 12 Youth population in 2015 (millions) High 12 Very High 9 Youth population in 2010 (millions) Medium 13 YDI level Figure 2.7  The number of Commonwealth countries at different YDI levels, 2010 and 2015 Low 15 Table 2.4  Commonwealth youth population by YDI level, 2010 and 2015 Source: Commonwealth Secretariat Figure 2.6  The number of countries worldwide at the different YDI levels, 2010 and 2015 Medium 44 Low 39 High 44 Medium 45 High 48 Very High 56 YDI levels in 2015 Very High 46 YDI levels in 2010 Low 44 34 Source: Commonwealth Secretariat high YDI categories have average scores that are in line with those of others in these categories. Aside from Pakistan, every country in the Commonwealth either maintained or improved its YDI level of youth development from 2010 to 2015. Table 2.4 shows the youth population in Commonwealth countries in 2010 and 2015 by their YDI level. 2.3  Inequalities in youth development While levels of youth development have improved across the world between 2010 and 2015, progress has been uneven. There are sharp disparities in youth development between and within different regions and countries. Although the YDI does not take into account inequalities within countries, the extent of inequality between countries can be gauged by analysing the gap between youth development levels of low and very high YDI countries. Nearly three-quarters of the world’s youth population is living in countries that fall in low or medium YDI categories. Figure 2.8 shows the average scores for the five domains of the YDI for each category of youth development. There are significant differences between countries that score very high and low on youth development in all five domains of the YDI, with the gap in Education being the largest, followed by Health and Well-being, then Employment and Opportunity. For both Education and Health and Well-being domains, the average score of very high youth development countries is nearly twice that of low youth development countries, indicating the persistence of high inequality between countries in these key social sectors despite a narrowing of the gap over the past five years. The gap between low and very high YDI categories for Commonwealth countries is largest in the domains of Health and Well-being and Education (Figure 2.9). Table 2.5 shows the average score of all the 18 indicators for low, medium, high and very high YDI categories. It can be observed that the average score for most indicators progressively improves from the low to the very high YDI category, reflecting the better living conditions for young people that exist in high YDI countries compared with low YDI countries, though the degree of improvement is not uniform across indicators. The indicator scores that vary the most between the low and very high YDI categories include digital native rates, youth mortality rates, literacy rates, HIV rates, existence of an account at a financial institution and adolescent fertility rates: • The proportion of young people who have been online for at least five years is on average 11 times higher in very high YDI countries than in low YDI countries (indicating a massive lag in access to and usage of digital technology in low YDI countries).