Here's a link for the report:
http://www.dubuque.k12.ia.us/MAP/2005docs/2005PlacementGuidelines.pdf
It comes from the norms in this report which goes into detail about sample size, etc.:
http://pickens.it.schoolfusion.us/m...ssionid=14d1e9266e4482d198ebc39c6e6bc9c3