The West continues to dominate as a U.S. region for assisted living communities, according to data reported Friday by the Centers for Disease Control and Prevention’s National Center for Health Statistics.

More than 40% (40.8%) of U.S. residential care communities were located in the West — which the U.S. Census Bureau defines as Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington and Wyoming — as of 2016, according to the National Study of Long-Term Care Providers. That’s up from 36.4% in 2012.

The West was the only region that saw an increase in the four-year period.

The South is the region with the second-highest percentage of assisted living communities. That region, however, had 28% of assisted living communities in 2016, down from 30.6% in 2012. The South includes Alabama, Arkansas, Delaware, District of Columbia, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia and West Virginia.

In the Midwest, the decrease was smaller: 22.9% in 2012 to 22.6% in 2016. The Midwest includes Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota and Wisconsin.

In the Northeast, the percentage of assisted living communities fell from 10.1% in 2012 to 8.6% in 2016. The Northeast region includes Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island and Vermont.

The study defined residential care communities as being state-regulated; having at least four beds; and providing room and board with at least two meals a day, around-the-clock, on-site supervision and help with activities of daily living. Communities licensed exclusively to serve the mentally ill or the intellectually or developmentally disabled populations were excluded from the percentages.