(a) The North American Industry Classification System (NAICS) has replacedthe Standard Industrial Classification (SIC) system.

 (b) The Establishments (counts) column includes those units which reported floorspace, plus those units where floorspace was not ascertained.   To obtain the number of reporting establishments for any NAICS, divide the entry in the Approximate Enclosed Floorspace column by the corresponding entry in the Average Enclosed Floorspace column.  For example, in the Total row, (12,836 million sq ft) divided by (71,257.0 sq ft) equals 180,137, which is the number of reporting establishments (weighted) of the 226,813 total establishments..

   Source: Energy Information Administration, Office of Energy Markets and End Use, Energy Consumption Division, Form EIA-846, '1998 Manufacturing Energy Consumption Survey.'