The Economic Census is conducted every 5 years in years ending in 2 and 7. Surveys are sent to mid-size and large businesses and a sample of small businesses. Survey questions are tailored to each industry and ask about number of employees, payroll, services, and sales. The data may be used to identify economic trends, compare communities, and compare individual businesses to industry averages.
"The North American Industry Classification System (NAICS) is the standard used by Federal statistical agencies in classifying business establishments for the purpose of collecting, analyzing, and publishing statistical data related to the U.S. business economy.
NAICS was developed under the auspices of the Office of Management and Budget (OMB), and adopted in 1997." --Census Bureau