Publicly traded companies in the U.S. recorded the lowest level of goodwill impairment since 2008, according to a new study.

The study, by the valuation firm Duff & Phelps and the Financial Executives Research Foundation, found that U.S. companies recorded $21 billion of goodwill impairment last year, the lowest aggregate impairment amount since 2008 and a 59 percent decrease from the $51 billion reported in 2012.

The average impairment amount was $108 million in 2013. This represents a 50 percent decline from the prior-year average and approaches the low of $86 million in 2009.

“This year’s study found that aggregate impairment is at its lowest level since 2008, reflecting a stronger economy and higher market valuations overall,” said Greg Franceschi, Duff & Phelps managing director and co-chairman of the AICPA Impairment Task Force, in a statement.

This is the sixth year that Duff & Phelps has prepared a goodwill impairment study. The latest study is based on financial information reported for the 2009-2013 calendar years by over 5,100 companies, representing 92 percent of market capitalization for U.S. based publicly traded companies as of Dec. 31, 2013.

The report found that aggregate goodwill impairment amount was no longer dominated by the top three impairment events for the year. The concentration of goodwill impairments attributable to the three largest impairment events declined from 47 percent in 2012 to 22 percent in 2013.
The study also indicated that 52 percent of the goodwill impairments were booked by three industries: materials, health care and industrials. In contrast, last year’s report found that 67 percent of the goodwill impairment was concentrated in the information technology, industrials and health care sectors.

Industrials had the largest percentage of companies with impaired goodwill (7 percent), followed by information technology and consumer discretionary (both at 6 percent).

Of the companies carrying goodwill, 8.6 percent recognized goodwill impairment in 2013, a decrease from 10.5 percent in 2012.