Patricia Aho’s departure as head of the Maine Department of Environmental Protection, announced Monday, makes her the 12th Cabinet-level commissioner to leave Gov. Paul LePage’s administration in the 4½ years since the governor took office.

Turnover is expected in Cabinet-level jobs under any governor. LePage had three of his commissioners depart in his first year on the job.

Meanwhile, six LePage commissioners (out of 13 Cabinet-level agencies) have remained in their posts since the 2011 start of the administration: Transportation Commissioner David Bernhardt, Professional and Financial Regulation Commissioner Anne Head, Health and Human Services Commissioner Mary Mayhew, Public Safety Commissioner John Morris, Agriculture, Conservation and Forestry Commissioner Walt Whitcomb, and Inland Fisheries and Wildlife Commissioner Chandler Woodcock.

Here are the 11 LePage administration commissioners who have moved on:

Darryl Brown — LePage’s first commissioner of the Department of Environmental Protection resigned in April 2011 after less than three months on the job after then-Attorney General William Schneider’s ruling that Brown’s appointment violated a state conflict-of-interest law due to his ownership of a development firm that dealt directly with the DEP. Brown later became director of the now-defunct State Planning Office before moving to Cianbro as director of the company’s east-west highway project.

Philip Congdon — LePage’s first choice to lead the Department of Economic and Community Development left the position in April 2011 after reports that he made remarks during a trip to Aroostook County that audience members said were racist and insulted the intelligence of Aroostook County residents.

Norman Olsen — LePage’s first commissioner of the Department of Marine Resources resigned in July 2011 — about six months after taking the job — citing a rift with LePage, resistance to his initiatives among DMR staff and an antagonistic relationship with the fishing community.

Maj. Gen. John W. Libby — Libby served as commissioner of the Department of Defense, Veterans and Emergency Management until February 2012, when he retired. Libby also served as adjutant general of Maine’s National Guard. He was originally appointed by Democratic Gov. John Baldacci.

Robert Winglass — Winglass stepped down as commissioner of the Department of Labor in August 2012 to retire. He had agreed to serve one to two years in the post.

Bill Beardsley — Beardsley served as commissioner of the Department of Conservation until his agency merged with the Department of Agriculture in August 2012, becoming the Department of Agriculture, Conservation and Forestry. LePage appointed Beardsley, former president of Husson University, to the state Board of Education.

Stephen Bowen — Bowen served as LePage’s education policy adviser at the start of the LePage administration before LePage tapped him to lead the Department of Education. Bowen left that job in September 2013 to take a job with the Washington, D.C.-based Council of Chief State School Officers, a national association for state education agency heads.

Joseph Ponte — Ponte, who served as commissioner of the Department of Corrections, left the LePage administration in March 2014 to oversee New York City’s jails under Mayor Bill de Blasio.

Sawin Millett — Millett, a state government veteran, retired in May 2014 after a 55-year career in various public-sector capacities. Millett served as commissioner of the Department of Administrative and Financial Services.

Jim Rier — Rier, who replaced Bowen as commissioner of the Department of Education, went on medical leave indefinitely in November 2014. The next month, LePage swore in education policy adviser Tom Desjardin as acting education commissioner.

Brig. Gen. James D. Campbell — Campbell replaced Libby as adjutant general of Maine’s National Guard and commissioner of the Department of Defense, Veterans and Emergency Management. LePage fired him in March shortly before he was supposed to make a speech to the Legislature on the state of the National Guard. LePage said he had lost faith in Campbell’s ability to lead the Guard. The firing followed a long controversy surrounding a planned conversion of the state’s 133rd Engineer Battalion to an infantry unit.