The Norwegian pupils in grade 5, which was the main population in 2015, had an average score of 549, which was higher than both Finland and Denmark. Again the Norwegian scores are significantly lower, mainly due to their lower age. With the change of main population to grade 5, the Norwegian score in Science was 538, which was slightly below the Swedish score of 540. In 2015, the Norwegian students in grade 9 had an average score of 512 in mathematics and an average score of 509 in science. These students are the same age as the Swedish grade 8 students. As shown in Figures 5-7, all the Nordic countries except Finland have had results with rather small variations around the OECD average during the whole period.