Construction firms added jobs in 44 states and the District of Columbia between January 2015 and January 2016, according to an analysis of US Department of Labor data released today by the Associated General Contractors of America.

Hawaii posted the largest year-over-year percentage increase in construction employment at 15.6%. However, California led in terms of total number of jobs added with 45,700 jobs added year over year.

“Construction remains vibrant in nearly every state and is adding workers at a faster clip than other industries in much of the country,” said Ken Simonson, chief economist for the association. “Contractors report they are optimistic that demand for construction will continue, but they worry about finding enough qualified workers.”

The six states that shed construction jobs during the past 12 months have been hurt by the steep drop in oil and gas drilling and coal mining. North Dakota lost the highest percentage and total number of jobs at 14.4% and 5,300 jobs.