On the heels of a sizeable decrease in April, the Architecture Billings Index (ABI) slowed even further in May. As a leading economic indicator of construction activity, the ABI reflects the approximate nine to twelve month lag time between architecture billings and construction spending. The American Institute of Architects (AIA) reported the May ABI score was 47.2, a slight decrease from a reading of 47.6 the previous month. This score reflects a continued decrease in demand for design services (any score above 50 indicates an increase in billings). The new projects inquiry index was 52.6, down from a mark of 55.0 in April, its lowest level in almost a year and a half.