Construction employment last month was at its highest number since February of 2009, according to analysis by the Associated General Contractors of America (AGC). AGC also notes the number of unemployed workers with construction experience shrank to a 14-year low, which may have an impact on the industry’s ability to meet growing demand.

“It is encouraging to see construction employment rising again, but the industry could hire many more workers if they were available,” says Ken Simonson, AGC’s chief economist. “The lack of experienced construction workers may be impeding the industry’s ability to start or complete new projects. The recent acceleration in construction spending may soon level off unless the sector can draw in more workers with the right skills.”

Employment in the industry totaled 6,383,000 in July. Overall construction employment rose by 6,000 from June to July, far below the monthly average of 19,250 between July 2014 and July 2015, Simonson notes. Meanwhile, employment at architectural and engineering services firms climbed by 3.6 percent since July 2014.

According to AGC, factors contributing to the shrinking pool of available labor include the retirement of aging workers, the departure of workers during the economic downturn and a lack of high school-level programs exposing students to opportunities in construction.