The AIA’s Architecture Billings Index (ABI), the institute’s indicator of nonresidential construction activity, has contracted for the first time in 25 months.

The ABI tracks architecture billings across the country, and as such, is indicative of what construction industry will be 9-to-12 months later. The March 2019 ABI, a measure of the national monthly billings rate, fell to 47.8 from 50.3 in February. The ABI measures month-over-month statistics, so a score below 50 means a decrease from the prior month, while a score over 50 reflects an increase.

“Though billings haven’t contracted in a while, it is important to note that it does follow on the heels of a particularly tough late winter period for much of the country,” said AIA Chief Economist Kermit Baker in a press release. “Many indicators of future work at firms still remain positive, although the pace of growth of design contracts has slowed in recent months.”

The regional statistics for March, which are calculated on a three-month basis instead of monthly, break down the figure further. According to the AIA, regional averages were as follows: the South 54.2, Midwest 48.7, West 47.2, and Northeast 43.5.

By sector, which is also calculated on a three-month average, mixed practice was reported at 53.1, commercial/industrial at 47.0, institutional at 48.9, and multi-family residential at 47.7.

The Project Inquiries Index for March, which is calculated monthly, was 59.8, while the Design Contracts Index, also reported monthly, held in positive territory at 50.8.