| | | 221118 | Other Electric Power
Generation | 6 | Other Electric Power
Generation 221118 | Electric Power Generation
22111 | Electric Power
Generation, Transmission
and Distribution 2211 | Utilities 221 | Utilities 22 |
| | | 22112 | Electric Power
Transmission, Control,
and Distribution | 5 | | Electric Power
Transmission, Control,
and Distribution 22112 | Electric Power
Generation, Transmission
and Distribution 2211 | Utilities 221 | Utilities 22 |
| | | 221121 | Electric Bulk Power
Transmission and Control | 6 | Electric Bulk Power
Transmission and Control 221121 | Electric Power
Transmission, Control,
and Distribution 22112 | Electric Power
Generation, Transmission
and Distribution 2211 | Utilities 221 | Utilities 22 |
| | | 221122 | Electric Power
Distribution | 6 | Electric Power
Distribution 221122 | Electric Power
Transmission, Control,
and Distribution 22112 | Electric Power
Generation, Transmission
and Distribution 2211 | Utilities 221 | Utilities 22 |
| | | 2212 | Natural Gas Distribution | 4 | | | Natural Gas Distribution 2212 | Utilities 221 | Utilities 22 |
| | | 22121 | Natural Gas Distribution | 5 | | Natural Gas Distribution 22121 | Natural Gas Distribution 2212 | Utilities 221 | Utilities 22 |
| | | 221210 | Natural Gas Distribution | 6 | Natural Gas Distribution 221210 | Natural Gas Distribution 22121 | Natural Gas Distribution 2212 | Utilities 221 | Utilities 22 |
| | | 2213 | Water, Sewage and Other
Systems | 4 | | | Water, Sewage and Other
Systems 2213 | Utilities 221 | Utilities 22 |
| | | 22131 | Water Supply and
Irrigation Systems | 5 | | Water Supply and
Irrigation Systems 22131 | Water, Sewage and Other
Systems 2213 | Utilities 221 | Utilities 22 |
| | | 221310 | Water Supply and
Irrigation Systems | 6 | Water Supply and
Irrigation Systems 221310 | Water Supply and
Irrigation Systems 22131 | Water, Sewage and Other
Systems 2213 | Utilities 221 | Utilities 22 |