NSSGA is the world’s largest mining association by product volume. Its member companies represent more than 90 percent of the crushed stone and 70 percent of the sand and gravel produced annually in the U.S. and approximately 118,000 working men and women in the aggregates industry. During 2007, a total of about 2.56 billion metric tons of crushed stone, sand and gravel, valued at $21 billion, were produced and sold in the United States.