| Value | Category | Cases | |
|---|---|---|---|
| 1 | Self-produced | 15707 | 
                                    
                                    73%
                                 | 
| 2 | Purchased | 5778 | 
                                    
                                    26.9%
                                 | 
| 3 | Received for free | 17 | 
                                    
                                    0.1%
                                 | 
| Sysmiss | 22803 |