| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 27 | 
                                    
                                    24.3%
                                 | 
| 0 | No time was spent | 51 | 
                                    
                                    45.9%
                                 | 
| 1 | 4 | 
                                    
                                    3.6%
                                 | |
| 2 | 3 | 
                                    
                                    2.7%
                                 | |
| 3 | 1 | 
                                    
                                    0.9%
                                 | |
| 5 | 1 | 
                                    
                                    0.9%
                                 | |
| 6 | 1 | 
                                    
                                    0.9%
                                 | |
| 10 | 7 | 
                                    
                                    6.3%
                                 | |
| 12 | 1 | 
                                    
                                    0.9%
                                 | |
| 14 | 1 | 
                                    
                                    0.9%
                                 | |
| 20 | 1 | 
                                    
                                    0.9%
                                 | |
| 30 | 3 | 
                                    
                                    2.7%
                                 | |
| 40 | 4 | 
                                    
                                    3.6%
                                 | |
| 60 | 3 | 
                                    
                                    2.7%
                                 | |
| 70 | 1 | 
                                    
                                    0.9%
                                 | |
| 80 | 2 | 
                                    
                                    1.8%
                                 |