United States NAEP Long-Term Trend Mathematics, Age 9

source: http://nces.ed.gov/nationsreportcard/lttdata/report.aspx

What is NAEP?

1. naep

   Web definitions

   1. The National Assessment of Educational Progress is the largest continuing and nationally representative assessment of what American students know and can do in core subjects. ...
      http://en.wikipedia.org/wiki/NAEP_(disambiguation)