SIC	Industry Description (1972)	Total # Employees (Male & Female)	Total # Female Employees
13	OIL AND GAS EXTRACTION	6,111
15	GENERAL BUILDING CONTRACTORS	1,969
16	HEAVY CONSTRUCTION CONTRACTORS	2,049
17	SPECIAL TRADE CONTRACTORS	3,396
32	STONE, CLAY, AND GLASS PRODUCTS	3,837
80	HEALTH SERVICES	18
TOTAL		17,380

*(1) By survey design, not all 2-digit SICs were surveyed. (2) The estimates for each 2-digit SIC apply only to the 3- and 4-digit SICs surveyed within the 2-digit SIC. Not all SICs were surveyed. (3) When using the estimates, standard errors associated with estimates should be considered. (4) Potential exposures to a chemical agent are categorized as actual (i.e., the surveyor observed the use of the specific agent) or tradename (i.e., the surveyor observed the use of a tradename product known to contain the specific agent). The estimates presented in the table combine both categories.