Hierarchical structure
+ 1 Managers
+ 2 Professionals
+ 3 Technicians and associate professionals
+ 4 Clerical support workers
+ 5 Service and sales workers
+ 6 Skilled agricultural, forestry and fishery workers
+ 7 Craft and related trades workers
+ 8 Plant and machine operators, and assemblers
+ 9 Elementary occupations
+ 0 Armed forces occupations
