| Value | Category | Cases | |
|---|---|---|---|
| 0 | 1 | 
                                    
                                    0.1%
                                 | |
| 1 | Primary or none | 487 | 
                                    
                                    32.9%
                                 | 
| 2 | Secondary | 607 | 
                                    
                                    41%
                                 | 
| 3 | Higher | 384 | 
                                    
                                    26%
                                 |