Furthermore the report suggests that  the global population weighted PM2.5 concentrations has increased by 11.2% from 39.7\(\mu\)g/m3 in 1990 to 44.2\(\mu\)g/min 2015 and the rapid increase in the concentrations was significant  from the year 2010 onwards as shown in Figure 4. These increases reflects the changes in air pollution levels in some of the most populous countries in the world such as China, India, Bangladesh and those in the European region. The highest increase in PM2.5 levels from 2010 to 2015 was experienced by Bangladesh and India whereas countries that are clustered at the bottom of Figure 4 such as the United States, Brazil, Russia, Indonesia and countries in the European Union have seen a slight decrease in PM2.5 levels since 1990.