New vehicle retail sales increased 5% year-over-year in May, however, the amount of people reporting that they’ll buy a new vehicle in the second half of 2018 is on the decline, according to Cox Automotive’s June 2018 Industry Update.

Last year was the first year that the auto industry saw a decline in new-vehicle sales in seven years. The fate of this year is still unclear, but the continued decline in new-vehicle sales will have an effect on the supply and value of used vehicles in the years to come.

Used vehicle sales this year remain slightly above the pace set in 2017; however, sales were down 1% year-over-year during May. Certified Pre-Owned sales were a bright spot for the used market in May, however, as sales for the segment were up 5%.

Looking at the fleet segment, commercial fleet sales increased 2% year-over-year, rental fleet increased 30%, and government fleet sales decreased 1%.

Related: First-Half 2018 Retail Sales Weakest in Four Years