About one in eight drivers on the road is uninsured, according to a new report from the Insurance Research Council (IRC).

After a seven-year decline from a high of 14.9% in 2003, the national uninsured motorist (UM) rate increased from 12.3% in 2010 to 13% in 2015. UM rates vary substantially among individual states, ranging from 4.5% in Maine to 26.7% in Florida.

The report finds that, despite the national increase, UM rates have dropped significantly in some states. Oklahoma’s UM rate has fallen from 25.9% in 2012 to 10.5% in 2015.

“The drop in uninsured motorist rates in several states certainly is good news,” said Elizabeth A. Sprinkel, Senior Vice President, IRC. “However, the increase in the countrywide rate is a concern. IRC is exploring why uninsured motorist rates vary so much across states and why the countrywide rate is once again be on the rise.”

The IRC report, “Uninsured Motorists, 2017 Edition”, examines data collected from 14 insurers representing approximately 60 percent of the private passenger auto insurance market in 2015.