| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 19 | 
                                    
                                    8.8%
                                 | 
| 0 | No time was spent | 78 | 
                                    
                                    36.3%
                                 | 
| 1 | 8 | 
                                    
                                    3.7%
                                 | |
| 2 | 20 | 
                                    
                                    9.3%
                                 | |
| 3 | 7 | 
                                    
                                    3.3%
                                 | |
| 4 | 2 | 
                                    
                                    0.9%
                                 | |
| 5 | 31 | 
                                    
                                    14.4%
                                 | |
| 10 | 19 | 
                                    
                                    8.8%
                                 | |
| 12 | 1 | 
                                    
                                    0.5%
                                 | |
| 15 | 4 | 
                                    
                                    1.9%
                                 | |
| 20 | 6 | 
                                    
                                    2.8%
                                 | |
| 25 | 4 | 
                                    
                                    1.9%
                                 | |
| 30 | 6 | 
                                    
                                    2.8%
                                 | |
| 32 | 1 | 
                                    
                                    0.5%
                                 | |
| 35 | 1 | 
                                    
                                    0.5%
                                 | |
| 36 | 1 | 
                                    
                                    0.5%
                                 | |
| 40 | 3 | 
                                    
                                    1.4%
                                 | |
| 48 | 1 | 
                                    
                                    0.5%
                                 | |
| 50 | 2 | 
                                    
                                    0.9%
                                 | |
| 95 | 1 | 
                                    
                                    0.5%
                                 |