AIA’s monthly Architecture Billings Index for April came in at a score of 29.5, a 3.8-point decrease from March’s dramatic fall to 33.3. The ABI is a leading economic indicator of construction activity in the U.S. and reflects a nine- to 12-month lead time between architecture billings and construction spending nationally, regionally, and by project type. A score above 50 represents an increase in billings from the previous month, while a score below 50 represents a contraction.