Flat glass prices inched down by 0.2 percent in March, according to the latest Producer Price Index (PPI) report.

Prices had been unchanged the month before after a 1.1-percent increase in January. They are up 5.8 percent since March of last year, and the flat glass index sits at 130.1.

The PPI program, according to the U.S. Bureau of Labor Statistics (BLS), measures the average change over time in the selling prices received by domestic producers for their output. The prices included in the PPI are from the first commercial transaction for many products and some services.

Final demand for construction was up 0.1 percent in March after decreasing by that same amount in February. That index is up 1.1 percent from a year ago.

Materials for construction ticked back up by 0.3 percent following a 0.2-percent decrease the month before, and those prices are down 0.2 percent from March 2015.

Price for construction machinery were up 0.3 percent in March after consecutive 0.1-percent decreases in each of the previous two months. That index is up a full 1 percent from a year ago.

In another report, import prices for glass and glassware increased 0.3 percent for the month after a 0.1-percent increase in February. Export prices in that category were unchanged for the second straight month.

Overall, the PPI for final demand fell 0.1 percent in March, seasonally adjusted. Final demand prices decreased 0.2 percent in February and advanced 0.1 percent in January. On an unadjusted basis, the final demand index dropped 0.1 percent for the year ended in March.

U.S. import prices increased 0.2 percent for the month, following a 0.4-percent drop the previous month. Prices for U.S. exports recorded no change in March after falling 0.5 percent in February.