Task: Text Simplification
Input (English): riaa website although total worldwide album sales are not calculated by any single entity , as of 2004 several industry sources estimated rush 's total worldwide album sales at over 40 million units.
Output (English): as of 2004 , several industry sources estimated rush 's total worldwide album sales are over 40 million units even though they are not calculated by any single entity by the riaa websi.