Oklahoma City's sales tax revenue is up for the first time in more than a year.

Budget Director Doug Dowler said Thursday that collections for the May reporting period grew 2.6 percent from May 2016.

After declines in 18 of the past 20 months, results could indicate the city's retail economy has turned a corner.

Sales tax is the city's single-largest source of revenue, vital to services such as police and fire protection.