| Value | Category | Cases | |
|---|---|---|---|
| 1 | Self-produced | 11809 | 
                                    
                                    63.1%
                                 | 
| 2 | Purchased | 6877 | 
                                    
                                    36.7%
                                 | 
| 3 | Received for free | 32 | 
                                    
                                    0.2%
                                 | 
| Sysmiss | 25587 |