The American Staffing Association’s Skills Gap Index identified 181 hard-to-fill occupations in the U.S. for the 12 months ended March 2015.

“With more than five million job openings going unfilled, businesses are concerned that their growth will be impeded because they cannot fill their talent pipelines,” said Richard Wahlquist, ASA president and chief executive officer. “The ASA Skills Gap Index assists businesses and their staffing firm partners in developing strategies to source qualified talent in occupations and in regions where demand significantly exceeds supply.”

Members can see the list of the 10 most difficult-to-fill jobs, and download the full ASA Skills Gap Index report for the first quarter of 2015, at americanstaffing.net.

The skills gap index was established by ASA, using a hiring indicator developed by ASA corporate partner CareerBuilder. It measures the level of difficulty (on a scale of one to 100, with lower scores indicating harder to fill) to recruit for a specific occupation based on demand, supply of active candidates, and total population working in it. The ASA Skills Gap Index concentrates on hiring indicator scores of 50 or less for hard-to-fill occupations, with a demand of 2,000 jobs or more. The ASA Skills Gap Index is updated quarterly.