LAWRENCEVILLE, Ga. — Black Book (div. of Hearst)’s Used Vehicle Retention Index for September stood at 116, a 1.9% increase from a year ago and a 0.5% increase from August, the firm reported this week.

The last time Black Book’s key index reached 116 was in October 2016. What’s more, the Index was up for all segments, ranging from a 0.26% increase for small pickups to a 1.82% increase for sporty car. The five segments that drove up the firm’s September index were:

1. Compact Crossover/SUV: +0.89% MOM

2. Mid-Size Crossover/SUV: +0.89% MOM

3. Compact Car: +0.89% MOM

4. Full-Size Pickup: +0.73% MOM

5. Mid-Size Car: +0.64% MOM

“The Index ratings over the last few months are a clear indication of the strength that has been present throughout the used-vehicle market in 2018,” said Anil Goyal, executive vice president of operations for Black Book. “What’s interesting this month is the broad strength in the market across all vehicle segments. It is unlikely for the Index to maintain this upward momentum, as we get to the end of the year when typical depreciation patterns are expected to set in.”

The Index dates back to January 2005, when Black Book published a benchmark index value of 100.0 for the market. During 2008, the index dropped by 14.1%. It then dropped by 6.4% in 2016 before rising from 113.3 to 123.0 by the end of 2011 as the economy picked up steam and used vehicle values rose. It continued to remain relatively stable, rising slightly until May 2014. That’s when the index peaked at 128.1.