I thought that was weird, too. So far everyone I know who's taken this test and posted their results to LJ has been scoring better than just about everybody else in their age groups, and I've seen a pretty wide range of scores. Also I want to see an age distribution of people who've taken the test, because the results claim that people in the 55-59 group have been scoring highest across the board, but I'm guessing that this test isn't all that popular in that age group, so the people who took it are a small self-selected sample of grammar nerds, who of course did really well on the test and skewed the data six ways from Tuesday. I also suspect that the testwriter cares way more about grammar than about statistics.