Mid-size car retention rates for model-year vehicles older than two years dropped this year after maintaining a similar retention rate over the previous four years.

Retention rates for 2014-MY vehicles dropped to 49%, which is 4% lower than the 53% for 2013-MY vehicles last year. Earlier years showed steady retention rate percentages between 53% and 55%, according to the Sept. 12 Black Book Market Insights report.

The report also spotlighted how sporty cars are currently leading the way for the ongoing drop in depreciation for car segments. The segment depreciated by 1.45%.

“The sporty car segment declined the most, following typical seasonal patterns as summer draws to a close. The car segments continue to experience a steeper decline in values in comparison to pickups and SUVs,” said Anil Goyal, senior vice president of automotive valuation and analytics.

With a volume weighting, overall car segment values decreased by 0.77% for the week ending Sept. 9. This is slightly higher than the depreciation rate of 0.69% seen in the previous four weeks.

Following sporty cars, full-size car (0.96%), luxury car (0.80%), and sub-compact car (0.80%) segments declined the most. Overall truck segment (including pickup, SUVs and vans) values continue to show consistency, decreasing by 0.44% last week.