Use of managed service providers has been increasing, but that use appears to have plateaued for now, according to research by Staffing Industry Analysts.

The three-year moving average of large firms that use an MSP was 63% this year, according to the new report “Workforce Solutions Buyers Survey: Trends in management strategies and priorities.” That’s unchanged from the three-year moving average taken last year, but down from the 66% recorded in 2015.

The three-year moving average had grown from just 42% in 2009.

It’s thought that some of the deceleration recorded this year in MSP use may be due to the trend of bringing contingent workforce programs in-house. The research found 13% had taken their contingent workforce program in house and 14% planned to do so in the next several years.

Use of vendor management systems, on the other hand, grew this year to a three-year moving average of 73%, up from 71% last year. Its three-year average was just 16% in 2006.

The report included 145 large firms in the Americas that use contingent labor. The full report is available to corporate members of Staffing Industry Analysts.