CRI calculates the aluminum recycling rate differently than does the Aluminum Association.  The AA counts all of the cans recycled in the United States -- even the used cans that have been imported from other countries specifically to be recycled.  CRI leaves these used beverage containers (UBC's) out of its calculations, contributing to a more accurate representation of the recycling rate in the USA.  CRI's method has been approved by the EPA.   The links below give more details about the calculation of aluminum can recycling rates.

Calculating the Aluminum Can Recycling Rate:
An explanation

Graph: Aluminum Can Recycling Rate: 2 methods of measuring (1990-2010)
Graph of the decline in the recycling rate from 1990-2010 according to CRI's measurement method, contrasted with the Aluminum Association's method