I didn't take the Nov test but I just wanted to let you know that your score is not based (at least entirely) on how others did on the test...
Your percentile is based on how others did, but your score comes from some other kind of statistical analysis done by ETS. You can verify this by looking at the scaled score vs. percentile data on the 4 practice tests... they don't always match up the same.
Consider the 8677 test vs. the 0177 test.
On 8677, 90th percentile was an 840, but on 0177, 90th percentile was a 900, so from this we see that your score isn't determined by how other students did.