Motor vehicle accidents claimed 227 fewer lives in 2017 compared to the earlier year, which equates to a 0.5% decline to 40,100, the National Safety Council (NSC) has found.

The small decline does not necessarily represent progress, but rather a plateau in 2017 along with the steepest two-year increase in over 50 years, according to the council. The 2017 assessment is 6% higher than the number of deaths in 2015. If the estimate holds, it will be the second consecutive year that motor vehicle deaths topped 40,000.

Injuries and costs for 2017 were also about 1% lower than in 2016 — with approximately 4.57 million people seriously injured in motor vehicle crashes in 2017 and costs to society totaling $413.8 billion.

For nearly 100 years, the NSC has tracked fatality trends and issued estimates. One factor known to impact motor vehicle fatality trends is an improved economy, which may be responsible in part for a 1% increase in miles driven from 2016-2017.

All estimates made by the NSC are subject to slight increases and decreases as the data mature. The organization collects fatality data every month from all 50 states and the District of Columbia and uses data from the National Center for Health Statistics, so that deaths occurring within one year of the crash and on both public and private roadways — such as parking lots and driveways — are included in the estimates.