This table shows the combined performance on a number of high-range intelligence tests, by year. For each test, the median scores by year were determined (in protonorms), as well as the number of scores in each year. Across the tests, the weighted median protonorm and the total number of scores were computed for each year. For information, the I.Q. corresponding to that protonorm is given (according to the current [2008] norming of protonorms to I.Q.s).
| Year | # scores | Median protonorm | Median I.Q. |
|---|---|---|---|
| 1995 | 18 | 353 | 130 |
| 1996 | 81 | 380 | 134 |
| 1997 | 38 | 391 | 137 |
| 1998 | 48 | 410 | 140 |
| 1999 | 89 | 433 | 145 |
| 2000 | 56 | 427 | 143 |
| 2001 | 136 | 420 | 142 |
| 2002 | 776 | 327 | 127 |
| 2003 | 256 | 387 | 136 |
| 2004 | 397 | 372 | 133 |
| 2005 | 196 | 402 | 139 |
| 2006 | 93 | 440 | 146 |
| 2007 | 94 | 395 | 139 |
| 2008 | 82 | 433 | 145 |
Remark: All of the Qoymans Multiple-Choice tests are included in this table, which provide very many scores (about 1000) with very low medians. This pulls down the overall median, which may therefore not be representative. If most of the Q.M.C. scores are excluded and only the latest version of the test used, the median rises to a bit over 400 (about I.Q. 140).
In 1995 the first tests were made available, it was hard to find candidates, and there were very few high scores. It started from zero, and no one knew about the tests initially. In the following years the tests became known in a wider circle, and more people took them, including some high scorers. Most candidates were from outside the Netherlands.
In 1997 The Glia Society was founded, and people started taking the tests purposely to qualify, resulting in higher scores. Also, in the following years the tests were published on the Internet which made them easier to find by people specifically interested in hard tests.
In 2000 the number of test submissions stayed lower than it could have been as test scoring was stopped for some months.
In 2001 the web site GliaWeb High-Range Intelligence Tests started, and it became possible to take tests via e-mail (Until then everything had been done by regular mail). This resulted in more test submissions.
In 2002 the Qoymans Multiple-Choice tests came, which appeared easy (online and multiple-choice) and were mostly free, resulting in very many submissions, but of a low median score level, with little or mostly no usable information reported by the candidates, who in many cases took the tests rather carelessly, which also resulted in lower reliability and validity (Those statistics depend not only on the test but also on the conscientiousness of the candidates). Over the next two years the Q.M.C. wave kept going but in a more controlled way, with fewer submissions, higher median scores, and higher quality on the whole.
2005 was a transitional year; During the first half the tests were free, and many submissions came in with relatively lower scores on average. Then, a high fee was asked for the first time - about € 20 to 25 except for Glia Society members - and fewer came in. The median score went up again, compared to the three previous years.
In 2006 and later, the number of submissions stayed fairly low because of the high fee (except for Glia Society members who can take the tests for free), and the median scores returned to the level of the period 1998-2001.
As an aside it can be noted that the maximum in sun spot activity of 2001 does not seem to have depressed performance on the tests. There is a theory by A. L. Chizhevsky and S. E. Ertel that such a maximum depresses culturally positive behaviour like creativity in art and science (which peak within plus or minus one year from a solar minimum), while it promotes disasters like revolutions, mass migrations, wars and so on (which peak within plus or minus one year from a maximum).
Actually the solar minimum of 2008 and low solar activity in the few years therebefore do go with higher scores, and in 2002 scores were very low indeed, but that can be explained much better as done in the above paragraphs (unless one includes those worldly causes with the influence of the sun).