Defense Department contractors in Afghanistan still outnumber U.S. troops by a 3-to-1 margin according to new research released this week, raising questions again about the role those workers play in the ongoing wars overseas and the oversight they receive.

The data, compiled by the Congressional Research Service and first reported by Politico, shows contractor numbers in both Iraq and Afghanistan dating back to fiscal 2007. Combined, the Defense Department spent more than $220 billion on contractors in both war zones for a variety of services and support.

The numbers show that the non-military defense workers have outnumbered U.S. troops in Afghanistan continuously since mid-2011, even as the numbers of both have drawn down steadily. But the ratio between the two groups continues to widen as administration officials work to reduce the roles played by armed military personnel in the war-torn country.

In early 2012, the number of defense contractors in Afghanistan peaked at more than 117,000 individuals, as compared to around 88,000 U.S. servicemembers.

Of those contractors, about 23 percent were working as supplemental security personnel, and more than 70 percent were foreign nationals receiving money from American companies and agencies.

The latest figures available, for the first few months of 2016, show nearly 29,000 defense contractors still in Afghanistan, with fewer than 9,000 U.S. troops stationed there. About two-thirds of the contractors were foreign nationals, but only about 10 percent were providing security services.

The report was made public by the Federation of American Scientists this week, and is online at the group’s web site.

Read More: Military Times

Featured Image – Afghan police shaking hands with the members (left) United Kingdom of private military company of contractors (right). – Defense Imagery.