| Value | Category | 
                                    
                    
                        | 0 |  | 
                                    
                    
                        | 1 | ...de día? (mañana/tarde) | 
                                    
                    
                        | 2 | ...de noche | 
                                    
                    
                        | 3 | ...de otro tipo? (rotativo, día y noche, guardias con franco | 
                                    
                    
                        | 9 | Ns./Nr. | 
                            
            Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.