Nearly half of US workers, 49.6%, are satisfied with their jobs, according to The Conference Board Job Satisfaction survey. This is up from 48.3% in 2014 and the highest level since 2005.

“The rise in workers’ job satisfaction is directly influenced by labor market improvements, and the latest annual job satisfaction trends mirror overall gains in the labor market,” said Michelle Kan, associate director, Knowledge Organization, and a co-author of the report. “The rapidly declining unemployment rate, combined with increased hiring, job openings and quits, signals a seller’s market, where the employer demand for workers is greater than the available supply.”

In addition to overall job satisfaction, the report looks at 23 components that contribute to job satisfaction, including wages, job security, promotion polices and health plans. The report finds that workers are most satisfied with their colleagues, 58.9%; interest in their work, 58.8%; their supervisors, 56.8%; the commute, 56.7%; and the physical workspace, 55.6%.

According to the report, US employees expressed the lowest satisfaction levels with aspects of work that are dependent on their evaluated performance. The job component with the lowest satisfaction is promotion policies at 23.8%, followed by bonus plans and the performance review process at 24.3% and 28.7% respectively.

“When the labor market tightens, employers have a more difficult time finding enough qualified and willing job candidates to fill available job openings,” said Gad Levanon, chief economist, North America at The Conference Board. “In these labor market conditions, workers are more satisfied with their jobs in several different ways. These include layoff rates and greater job security, more job opportunities and more job switching, increased wages and increased employer efforts to retain workers.”

The Conference Board Job Satisfaction survey results are based on workers’ perceptions of their current role and workplace environment. The survey questions are asked as part of The Conference Board Consumer Confidence Survey.