Note: 5th to 95th percentile is about 3.3 SD. For some strange reason the SD in developed, homogeneous countries (e.g., Japan, Korea, Norway, Netherlands, etc.) is roughly 12 plus or minus about one in Rindermann’s results, not 15. They claim they normalize the educational achievement scores to a “Greenwich (=UK?) mean IQ” of 100 with SD 15, but the SD for their UK entry is about 14, unless I made an arithmetic error.
Rindermann, in an earlier paper titled The g‐factor of international cognitive ability comparisons: the homogeneity of results in PISA, TIMSS, PIRLS and IQ‐tests across nations, showed that country IQ estimates of Lynn and Vanhanen were consistent with the educational performance data, and that a country level “G” factor explains most of the variation. The Rindermann link above goes to a 120 page pdf that contains Rindermann’s paper and lots of commentary from leading intelligence researchers. Apparently his straightforward compilation of data had a big impact in that community ;-)
[See here for scatterplots of L-V estimates of national IQ vs tests of educational achievement.]