As auto loan debt continues to soar, so has the number of people who are behind on their vehicle loans. By the end of 2018, more than 7 million Americans were 90 days or more behind on their car payments, according to the data released by the New York Federal Reserve.

“The substantial and growing number of distressed borrowers suggests that not all Americans have benefited from the strong labor market and warrants continued monitoring and analysis of this sector,” Fed economists said in a report regarding U.S. consumer debt.

The massive surge in delinquencies was followed with a $584 billion increase in total auto loan debt, making it the highest jump since the New York Fed began keeping track 19 years ago.

On the other hand,  the total level of overall credit quality actually improved. Those at the lower end of the spectrum declined to 22 percent of the total share, while 30 percent of the $1.27 trillion in total auto debt is now held by those on the higher end of the scale, as CNBC reports.

Those numbers “would suggest that the overall auto loan stock is the highest quality that we have observed since our data began in 2000. However, with growth in auto loan participation, there are now more subprime auto loan borrowers than ever, and thus a larger group of borrowers at high risk of delinquency,” the report said.

The debt issued by auto finance companies, rather than at the dealer level, is responsible for the majority of growth by less-qualified borrowers. 6.5 percent of the total auto finance debt was past due in the fourth quarter. The debt gathered from the 90-day past due category was 2.4 percent in 2018, compared to a low of 1.5 percent in 2012.