| Value | Category | Cases | |
|---|---|---|---|
| 1 | Self-produced | 16649 | 
                                    
                                    77.2%
                                 | 
| 2 | Purchased | 4674 | 
                                    
                                    21.7%
                                 | 
| 3 | Received for free | 230 | 
                                    
                                    1.1%
                                 | 
| Sysmiss | 22752 |