| Value | Category | Cases | |
|---|---|---|---|
| 1 | Self-produced | 11729 | 
                                    
                                    87.3%
                                 | 
| 2 | Purchased | 1363 | 
                                    
                                    10.1%
                                 | 
| 3 | Received for free | 344 | 
                                    
                                    2.6%
                                 | 
| Sysmiss | 30869 |