Construction employment in July climbed to the highest level since February 2009, while the number of unemployed workers with construction experience shrank to a 14-year low, according to an analysis of employment data by the Associated General Contractors of America. Association officials cautioned in a release that the diminishing pool of available qualified labor may be having an impact on the industry’s ability to meet growing demand. “The sector’s job gains in the past five months have been intermittent and relatively sluggish despite signs of accelerating demand for construction,” Ken Simonson, the association’s chief economist, said in the release.