Fig. 3From: Education-related inequalities in beliefs and behaviors pertaining to COVID-19 non-pharmaceutical interventionsChange over time in education-related inequality in four COVID-19 prevention and testing indicators: crude Slope Index of Inequality (SII), globally and by country income group (UMD-CTIS, June–December 2021). Notes: The line indicates the median and the shaded area indicates the interquartile range (middle 50% of study country estimates). Black dashed line shows no inequality (zero)Back to article page