Analysis
NAICS 92112 is the 2022 NAICS industry for legislative bodies, part of 9211 (Executive, Legislative, and Other General Government Support).
It has only one more detailed code, 921120, which covers exactly the same activities; the definition, index entries and statistics are on that page.
County Business Patterns excludes public administration, so there is no establishment count for it.
Official definition
See industry description for 921120.
Source: US Census Bureau, NAICS 2022 Manual.