www.pmmag.com/articles/87701-census-breakdown
        
        
        Census Breakdown
May 1, 2001
        There are 84,876 plumbing-heating-cooling contractor establishments, according to the updated national Plumbing, Heating and Air Conditioning Contractors economic census issued by the U.S. Census Bureau. 
          
        
      Here is a breakdown of establishments by number of employees:
- 1 to 4 employees	48,446
5 to 9 employees 17,814
10 to 49 employees 16,337
50 to 99 employees 1,481
100+ employees 798