Utility System Construction
Net profit margin rank: 95
Net profit margin: 0.88%
Change in 2009-2010 sales: –14.51%
Number of firms: 20,421
Contractors and construction companies that install water and sewer lines, oil and gas pipelines, and power and communication lines have seen their payroll-to-sales ratio (payroll expense as a percentage of sales) rise from about 10 percent to 15 percent since 2006.