Four-yearly Wage Structure Survey 
Sample errors
Studies completed. National total 
Unidades: %

All studies	0,37	
I. Without studies	3,9	
II. Primary education	1,43	
III. Secondary education I	0,9	
IV. Secondary education II	1,35	
V. Intermediate-level vocational training	1,39	
VI. Advanced vocational training	1,32	
VII. University diploma-holders or the equivalent	1,39	
VIII. University graduates, advanced engineers and doctors	1,37	
Notas:
Fuente: National Statistics Institute