| Value | Category | Cases | |
|---|---|---|---|
| 1 | First quartile | 259 | 
                                    
                                    10.8%
                                 | 
| 2 | Second quartile | 424 | 
                                    
                                    17.7%
                                 | 
| 3 | Third quartile | 424 | 
                                    
                                    17.7%
                                 | 
| 4 | Fourth quartile | 912 | 
                                    
                                    38%
                                 | 
| 5 | Don't know | 349 | 
                                    
                                    14.5%
                                 | 
| 6 | Refused | 32 | 
                                    
                                    1.3%
                                 |