A quick, glossy brochure. Look for you score to be in the top or second row, then see what grade that is:
http://www.nwea.org/sites/www.nwea.org/files/resources/NWEA_Comparative_Data.pdf

The full description of the MAP score norming data. Look at the percentiles by grade in appendix B, starting on page 51:
http://www.nwea.org/sites/www.nwea.org/files/resources/NWEA_2011_RIT_Scale_Norms.pdf