Online shopping is growing faster than the rest of the retail sector, with the number of establishments growing 27.4% between 2011 and 2012, according to United States Census Bureau statistics released today. The bulk of those companies—and their employees—are in California.

The new statistics come with an interactive map, which pulls data from the County Business Patterns: 2012 report. The map allows users to filter by state or county and type of retail—all, online, mail-order and auction—to analyze the number of establishments, employees and the average wage.

Looking at pure numbers, California has the most online retailers with 4,211 followed by Florida with 2,169 and New York with 1,920. Wyoming has the fewest number of online retailers with 33. California also employs the largest number of online retail employees with 35,089, followed by New York with 15,500 and Florida with 12,673. Wyoming again comes in last for the number of online retail employees with just 56.

The U.S. Census Bureau has a theory about why the number of employees is clustered around major metro areas. “Unlike traditional stores, which are located throughout the country, online shopping establishments and jobs are in concentrated areas,” says William Bostic Jr., the Census Bureau’s associate director for economic programs.

The counties that experienced the most online retail job growth from 2011 to 2012 were in Southern California and metro areas of such large cities as New York City, Chicago, Memphis, Las Vegas and Minneapolis.

When the data filter is switched to wages, online retail employees make the most in counties with large population centers: $84,208 in King County, Washington, and $65,226 in Hennepin County, Minnesota, where Minneapolis is located. Those wages are much higher than the average wages for all retail employees in those counties—$33,009 and $27,745 respectively.