To Mark:
My daughter got 98.5% for her composite (20) and 79 in total. Based on your understanding, the 98.5% is calculated from the last two year statistics.
Am I right?
Yes.
From the 2011 summary:
This statistical summary is based on scores from an even larger
sample of NUMATS test-takers, including all 2009 and 2010 NUMATS test-takers (over 50,000 students).
This is phrased in a slightly ambiguous way, but based on the counts I read it as including only 2009 and 2010.
Also you need to bear in mind that the summary data is "% scoring same or worse", so even if the data source were the 2011 data, it would be telling you that 98.5% scored 81 or lower total (the top total which gets a 20 composite), and it wouldn't mean that a 79 total is in the top 2%.
Just so there is no misunderstanding, that is a fantastic score and I am in no way meaning to disparage it. I'm just talking about how to interpret the statistics vs the cutoffs.