| Value | Category | Cases | |
|---|---|---|---|
| 1 | Are taken directly from establishment records | 58 | 
                                                                 
                                    
                                    15.5%
                                 
                                                             | 
                                                        
                    
| 2 | Are estimates computed with some precision | 270 | 
                                                                 
                                    
                                    72%
                                 
                                                             | 
                                                        
                    
| 3 | Are arbitrary and unreliable numbers | 5 | 
                                                                 
                                    
                                    1.3%
                                 
                                                             | 
                                                        
                    
| 4 | Are in some case taken from books and in some case estimates | 42 | 
                                                                 
                                    
                                    11.2%
                                 
                                                             |