Hi climbingupup,
To start, percentiles change over time (and the percentile data that you refer to is actually from a 4-year period - from 2015 to 2018 - not from the entire history of the Exam). In addition, people who take the GMAT multiple times - but score around the same general 'level' each time - can skew the percentiles for the overall group. This is meant to say that over the history of the exam, about 2/3 of GMATers have scored in the 400-600 range - and that will likely continue to be a reasonable approximation for what will happen in the future. Of course, none of this means much to how well YOU might perform on the GMAT, so it's important to not get too distracted by this information.
About a week ago, you posted that a School had asked you for your Unofficial Score information (even though you had submitted your Official Score Report). Has there been any follow-up from the School on this issue?
GMAT assassins aren't born, they're made,
Rich