Engineering News Record (ENR) provides an annual study that ranks contractor companies based on the construction revenue generated outside of each company's home country. The Top 250 International Contractors index ranks companies based on their international revenues. The site also offers the following rankings: the Top 500 Design Firms, the Top 200 Environmental Firms, the Top 100 Green Design Firms, and the Top 600 Specialty Contractors. Users are also able to access rankings from previous years.