CBP data indicates that there are more establishments categorized as retail trade businesses with between one and four employees in 21215 than in any other category.
The following table shows how many construction businesses with between one and four employees were in 21215 during the period from 2012 to 2016.
Construction businesses with between one and four employees in 21215 (2012-2016)
Year
Total businesses
2012
25
2013
23
2014
22
2015
25
2016
26