The demand for workers in Washington continued to heighten this spring, according to a new report released by the Employment Security Department.

Based on a survey of more than 15,000 Washington businesses, an estimated 81,532 jobs went unfilled statewide in April, an increase of nearly 11,000 compared to a year earlier. It was the highest number of vacancies in the survey’s four-year history.

Registered nurses topped the list of occupations in demand, with 4,802 vacancies. Other health-care jobs that went wanting were licensed practical nurses, nursing aides, orderlies and attendants. All told, health care accounted for 18 percent of the job vacancies statewide, the largest of any industry.

Cashiers ranked second, with 2,526 job vacancies, followed by retail salespeople, with 1,749 openings, and waiters and waitresses, with 1,516.

“Finding qualified health-care professionals is a challenge in Washington and throughout the nation,” said Karen Lee, Employment Security commissioner. “There are plenty of people who are interested in this type of rewarding career, but our education and training systems aren’t keeping up. We need a long-term, coordinated effort by our hospitals, colleges and lawmakers to address this critical workforce need.”

King County accounted for 52 percent of the unfilled positions, which was somewhat higher than its 40 percent statewide share of employment. The biggest rise in vacancies occurred in Chelan, Okanogan, Grant, Douglas and Adams counties, which experienced a 91 percent increase.

More than half of the vacancies were with firms with 100 or more employees. Further, 69 percent of the vacancies were full-time positions versus 31 percent part-time.

While many of the occupations require some level of higher education or specialty training, more than half required a high school diploma or less. Management occupations offered the highest median wage, at $31.25, while the agriculture and accommodation industries had a median hourly wage of less than $8.

“Education continues to be a big factor in getting higher-paid jobs,” Lee said.

The full Washington State Job Vacancy Survey report is available online at http://www.workforceexplorer.com .