| Value | Category | Cases | |
|---|---|---|---|
| 1 | Are taken directly from establishment records | 54 | 
                                                                 
                                    
                                    23.2%
                                 
                                                             | 
                                                        
                    
| 2 | Are estimates computed with some precision | 141 | 
                                                                 
                                    
                                    60.5%
                                 
                                                             | 
                                                        
                    
| 3 | Are arbitrary and unreliable numbers | 15 | 
                                                                 
                                    
                                    6.4%
                                 
                                                             | 
                                                        
                    
| 4 | Are in some case taken from books and in some case estimates | 23 | 
                                                                 
                                    
                                    9.9%
                                 
                                                             |