| Value | Category | 
                                    
                    
                        | 1 | I do not smoke | 
                                    
                    
                        | 2 | At home | 
                                    
                    
                        | 3 | At school | 
                                    
                    
                        | 4 | At work | 
                                    
                    
                        | 5 | At friends' houses | 
                                    
                    
                        | 6 | At social events | 
                                    
                    
                        | 7 | In public places | 
                                    
                    
                        | 8 | Other | 
                                    
                    
                        | Sysmiss |  | 
                            
            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.