Is that really the case? The article says "Bangladesh, India, Nepal and Pakistan are in order the top four most polluted countries". While there are certainly "0.1%" people in those countries, I highly doubt they're responsible for a meaningful amount of the pollution. For one, rich people use far less polluting technologies. Cooking and heating with electricity causes far less pollution than the poor burning biomass or coal. Furthermore, their population is small by definition, so even if they somehow pollute 10x more than average, their contribution is only 1%.

That percentage keeps getting smaller every year huh.