PMC full text:

Figure 5

An external file that holds a picture, illustration, etc.
Object name is gr5.jpg

Age-standardised disability-adjusted-life-years (DALY) rates for (A) migraine and (B) tension-type headache by 21 Global Burden of Disease regions by Socio-demographic Index (SDI), 1990–2016

The solid black line represents expected values based on SDI from a regression of all location data over the entire 1990 to 2016 estimation period.