The number of dermatologists per capita in the U.S. has surged more than 20 percent since the mid-90s, but a new study suggests access to care may have improved more in cities than in rural areas.

Nationwide between 1995 and 2013, the number of dermatologists rose 21 percent, from 3.02 for every 100,000 people in the population to 3.65 for every 100,000 residents, researchers report in JAMA Dermatology. Over that time, however, the chasm between urban and rural America widened.