| Value | Category | 
                                    
                    
                        | -9 | No answer | 
                                    
                    
                        | -7 | Not sure | 
                                    
                    
                        | 0 |  | 
                                    
                    
                        | 1 | Yes | 
                                    
                    
                        | 2 | No | 
                                    
                    
                        | 68 |  | 
                                    
                    
                        | 73 |  | 
                                    
                    
                        | 100 |  | 
                                    
                    
                        | 120 |  | 
                                    
                    
                        | 150 |  | 
                                    
                    
                        | 160 |  | 
                                    
                    
                        | 170 |  | 
                                    
                    
                        | 200 |  | 
                                    
                    
                        | 220 |  | 
                                    
                    
                        | 230 |  | 
                                    
                    
                        | 250 |  | 
                                    
                    
                        | 280 |  | 
                                    
                    
                        | 300 |  | 
                                    
                    
                        | 500 |  | 
                                    
                    
                        | 600 |  | 
                                    
                    
                        | 1000 |  | 
                                    
                    
                        | 1400 |  | 
                                    
                    
                        | 1700 |  | 
                                    
                    
                        | 3000 |  | 
                                    
                    
                        | 3200 |  | 
                                    
                    
                        | 4050 |  | 
                                    
                    
                        | 20000 |  | 
                            
            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.