Some percentiles/RIT scores. The highest listed here is 95.

https://www.nwea.org/content/uploads/2015/06/2015-MAP-Comparative-Data-One-Sheet-AUG15.pdf

The 2015 norm data are not available to the general public at the level of granularity you are likely seeking:

https://legacysupport.nwea.org/support/article/norms-study-resources


...pronounced like the long vowel and first letter of the alphabet...