In eStatement Studies you'll find Financial Ratio Benchmark (FRB) figures, broken down by US Region and revenue quartile, for a very large number of industries.
Look here for smaller and specialized industries, like Adhesive Manufacturing or Automobile Driving Schools.
You can sort ratios by Assets or by Sales.
The North American Industry Classification System (NAICS) is used to organize industry information. It's designed to produce common industry definitions for Canada, Mexico, and the United States. It is a hierarchical classification system, offering five levels of detail. Codes are assigned to an industry based on products and services provided by the industry.
Industries are represented by a six-digit number. The first two digits designate the economic sector: manufacturing, agriculture, wholesale, retail, professional services, etc. The subsequent digits designate subsectors and industry groups.
Each digit in the code is part of a series of progressively narrower categories.
72 - Accommodation and Food Services
722 - Food Services and Drinking Places
7225 - Restaurants and Other Eating Places
722511 - Full Service Restaurants
The Standard Industrial Classification (SIC), an earlier U.S. system, is still used by some sources.