| Value | Category | Cases | |
|---|---|---|---|
| 1 | Are taken directly from establishment records | 16 | 
                                    
                                    10.2%
                                 | 
| 2 | Are estimates computed with some precision | 92 | 
                                    
                                    58.6%
                                 | 
| 3 | Are arbitrary and unreliable numbers | 0 | 
                                    
                                    0%
                                 | 
| 4 | Are in some case taken from books and in some case estimates | 49 | 
                                    
                                    31.2%
                                 |