US staffing companies employed an average of 3.3 million temporary and contract workers per week in 2015, up 2.6% from 2014, according to data released by the American Staffing Association.

During all of 2015, staffing companies hired a total of 15.9 million temporary and contract employees — the highest number since 2000. The average length of employment with a staffing company was 10.7 weeks in 2015, slightly shorter than the tenure of 11.3 weeks in 2014.

In the fourth quarter of 2015, average weekly staffing employment totaled 3.4 million workers, up 2.8% from the third quarter and 0.4% more than in the fourth quarter of 2014.

The ASA staffing employment and sales survey is conducted on a quarterly basis, covering approximately 10,000 establishments.