After several years of modest growth following the recession, the interior design industry experienced a surge of activity in 2015 that continued into the first half of this year. Although demand softened somewhat in the third quarter, in most areas of the country the industry has made a full recovery.

But not in all. While some states have seen big gains, others are still struggling to return to their prerecession level, as indicated by data from the U.S. Bureau of Labor Statistics (BLS).

An analysis of BLS State Occupational Employment and Wage Estimates (OES) for interior designers for the years 2010 to 2015 (the most recent available annual data) shows most states have rebounded since the industry contracted from its peak following the economic downturn, which began in late 2008 but had its biggest impact on the industry in 2010-2011.

About half the states' estimated figures for 2015 show employment at or around prerecession levels. (BLS data does not include self-employed designers.) Some states have even well exceeded those levels, and others have made a big comeback after two or more years of substantial declines.

A few, however, have experienced erratic growth and have yet to reach a healthy recovery.

Since 2010, 13 states have exceeded their prerecession employment levels by 30 percent or more, as of May 2015. Five have seen gains of more than 100 percent. Utah went from a low of 190 employed designers in 2012 to 520 in 2015, an astounding increase of 173 percent in just three years.

Others include South Dakota (133 percent), Alabama (122 percent), Rhode Island (111 percent) and North Dakota (100 percent). Close behind are Oklahoma (95 percent), Mississippi (92 percent) and Nevada (90 percent). Rounding out the list are Colorado, the District of Columbia, Illinois, Maryland, Massachusetts, Tennessee, Texas and Washington.

In terms of numbers of employed designers, Texas leads the pack for biggest gains, having added 1,650 positions between 2011 and 2015, for a total of 4,780. California continues to hold first place as the state with the most interior designer employees 6,770 but it experienced fewer highs and lows during the period from 2010 to 2015.

Other states with a big boost in employment are Illinois (890 new positions), New Jersey (780), Ohio (740) and Colorado (690). Several other states — Massachusetts, Wisconsin and Utah— each exceeded 300 new positions.

Nine states have made notable comebacks in just the past two years. Mississippi, for example, by 2013 had lost about a third of its interior design employees (50 positions) but rallied, reaching 260 employees in 2014. Nevada's employment level fell from 370 in 2010 to 210 by 2013, but it rebounded to 400 by 2015. In addition to Utah, Rhode Island and Ohio (mentioned above), Wisconsin, Michigan, Kansas and Virginia have also enjoyed resurgences in hiring during 2014-2015.

Several states have not been so fortunate.

In Connecticut, interior design employment waxed to 980 designers in 2013 but had waned to 620 by 2015, a decline of 37 percent. Minnesota, which reported a prerecession level of 1,090 employees, fell to 730 in 2015, a drop of 33 percent. And South Carolina, which bounced back to 470 employees in 2012, counted only 390 in 2015, a 17 percent loss. Oregon's employment levels have see-sawed throughout the post-recession period, jumping from 300 in 2011 to 640 in 2013, up to 850 in 2014, and then back down to 750 last year.

Looking across the data, it is difficult to say what accounts for the rise and fall of activity in particular states. Interior design activity is dependent on many factors — the overall health of the economy (federal, state and local), personal income and worth, construction activity, housing prices, population density, consumer confidence, lifestyles, attitudes toward luxury and consumerism, and more.

In some cases, such as in Utah, Colorado, Nevada and the Dakotas, there is a clear link between overall growth within the state and renewed demand for services. In other cases — Rhode Island, perhaps — the location of firms may have less to do with their hiring patterns than the source of their clients.

In any case, given the significant increases in hiring over the past two years and the recent slowdown in demand for services, we can expect to see less volatility in employment for 2016 and possibly 2017.