Flat glass prices increased in August, regaining the upward trend they’ve seen for much of the year.

According to the latest Producer Price Index Report (PPI) issued this week by the U.S. Labor Department, flat glass prices jumped 0.7 percent from July to August, after seeing their first decrease since January the month before. The flat glass index sits at 121.5.

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

The latest bump in prices puts them up 2.2 percent since August of 2013.

Flat glass prices spiked 1.7 percent from March to April and saw an increase of 0.6 over the two months prior. That, combined with a 0.2 increase in May and June, equaled a 2.5 percent spike in prices the prior five months before July’s slight drop.

Meanwhile, in another report, import prices for glass and glassware saw a very slight dip of 0.1 percent in August. Import prices remained stagnant in June and July after decreasing in each of the three months prior. Prices in that category are up 0.5 percent from a year ago.

Export prices for glass and glassware, on the other hand, bumped slightly at 0.2 percent. Export prices were flat in July after a slight 0.1-percent dip the month before. Export prices for glass and glassware increased 0.9 percent in April and May combined and are up 1.5 percent from this time last year.

Prices of materials for construction jumped 0.4 percent from July to August after increasing 0.8 in the three months prior. Prices in that category are up 2.9 percent from August 2013. Final demand for construction stayed flat in August after a 0.5-percent increase in July. It is up 3.2 percent from a year ago.

On the whole, the PPI for final demand was unchanged in August, seasonally adjusted. Final demand prices advanced 0.1 percent in July and 0.4 percent in June. On an unadjusted basis, the index for final demand increased 1.8 percent for the 12 months ended in August.

In August, a 0.3-percent rise in prices for final demand services offset a 0.3-percent decrease in the index for final demand goods.

Overall prices for U.S. imports decreased 0.9 percent in August following a 0.3-percent decline in July. Export prices declined 0.5 percent in August, after ticking up 0.1 percent.