Achieving high average or median test score among students is important problem for a country. However, it is extremely important not to forget who is left on the bottom line. Decreasing number of low performing students is equally important.
Percent of student performing low at least in one subject is high and exceeds 25% for more than half countries. Among low performing students nearly a half perform low in all three subjects. Those students who perform low in one or two subjects mostly have difficulties with math.
To see concrete values hover over a bar, for data exploration try country filters on the right panel.
Notes:
Low Performance