| Value | Category | Cases | |
|---|---|---|---|
| 1 | Are taken directly from establishment records | 68 | 
                                    
                                    61.3%
                                 | 
| 2 | Are estimates computed with some precision | 36 | 
                                    
                                    32.4%
                                 | 
| 3 | Are arbitrary and unreliable numbers | 1 | 
                                    
                                    0.9%
                                 | 
| 4 | Are in some case taken from books and in some case estimates | 6 | 
                                    
                                    5.4%
                                 |