For further information, please refer to the US Census Bureau's Annual Services release, online at http://www.census.gov/services/.
Source: US. Bureau of the Census
Release: Annual Services Survey
US. Bureau of the Census, Total Expense for Offices Of Mental Health Practitioners, excluding Physicians, Establishments Subject To Federal Income Tax, Employer Firms [EXPEF62133TAXABL], retrieved from FRED, Federal Reserve Bank of St. Louis https://research.stlouisfed.org/fred2/series/EXPEF62133TAXABL/, August 4, 2015.