Just looking over previous data - last year's 50th and 90th percentiles were about 7.5 and 14, 2014 were 11 and 18, 2013 were 9.5 and 17. So it appears that a raw number isn't very meaningful - it varies so much year by year. I think I heard my DD12 mention a 17 talking to one of her friends, but I think that may have been an old test earlier this week as practice with her gifted group that's been preparing. And the statistical data will be needed to put any score in context.