Four-yearly Wage Structure Survey Four-yearly Wage Structure Survey. 2006 Variation coefficients for the gross annual earnings by main groups of the NCO-94 Unidades: % All occupations;0,45; A. Public administration management and management of companies with 10 or more employees;1,91; B. Management of companies with less than 10 employees;1,23; D. Professions associated with 2nd and 3rd cycle university degrees and the like;1,29; E. Professions associated with a 1st cycle university degree and the like;1,12; F. Support technicians and professionals;1,3; G. Administrative type employees;0,91; H. Catering services workers and personal services workers;1,22; J. Protection and security service workers;4,1; K. Retail workers and the like;1,66; L. Workers skilled in agriculture and fishing;3,73; M. Skilled construction workers, except machinery operators;2,06; N. Skilled extractive industry workers, metallurgy, construction, machinery and related trades workers;1,09; P. Skilled workers from the graphic arts, textile and preparation, elaboration of food, cabinetmakers, craftspersons and other similar industries;1,31; Q. Fixed machinery and industrial installation operators fitters and assemblers;0,77; R. Mobile machinery drivers and operators;1,48; S. Unskilled service workers (except transport);1,27; T. Agriculture, fishing, construction, manufacturing and transport labourers;1,47; Notas: Fuente: National Statistics Institute