The diffusion index of coincident economic indicators, a key government-devised measure to assess the state of the economy, pointed in May to an expansion for the 13th consecutive month, the Economic Planning Agency said in a preliminary report released Wednesday.

The index registered a preliminary 62.5 percent in May. A reading above 50 percent is thought to indicate an economic expansion, while a reading below that level is considered to indicate a contraction.

The diffusion index of leading indicators, which is considered to forecast activity several months ahead, was at 57.1 percent in May, moving back above the 50 percent mark after dropping below it in April for the first time in 14 months.