| Value | Category | Cases | |
|---|---|---|---|
| -9 | 724 | 
                                
                                19.3%
                             | |
| 44 | Vaccination given but no date recorded | 13 | 
                                
                                0.3%
                             | 
| 55 | invalid dates | 30 | 
                                
                                0.8%
                             | 
| 66 | Vaccination given but date not legible | 5 | 
                                
                                0.1%
                             | 
| 99 | Not Applicable | 2977 | 
                                
                                79.4%
                             | 
| Sysmiss | 203 |