| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 | 
                                    
                                    0%
                                 | 
| 0 | No time was spent | 44 | 
                                    
                                    29.3%
                                 | 
| 3 | 2 | 
                                    
                                    1.3%
                                 | |
| 5 | 4 | 
                                    
                                    2.7%
                                 | |
| 7 | 1 | 
                                    
                                    0.7%
                                 | |
| 8 | 1 | 
                                    
                                    0.7%
                                 | |
| 10 | 18 | 
                                    
                                    12%
                                 | |
| 14 | 1 | 
                                    
                                    0.7%
                                 | |
| 15 | 1 | 
                                    
                                    0.7%
                                 | |
| 16 | 1 | 
                                    
                                    0.7%
                                 | |
| 20 | 14 | 
                                    
                                    9.3%
                                 | |
| 25 | 1 | 
                                    
                                    0.7%
                                 | |
| 30 | 5 | 
                                    
                                    3.3%
                                 | |
| 35 | 1 | 
                                    
                                    0.7%
                                 | |
| 40 | 13 | 
                                    
                                    8.7%
                                 | |
| 50 | 13 | 
                                    
                                    8.7%
                                 | |
| 60 | 13 | 
                                    
                                    8.7%
                                 | |
| 80 | 5 | 
                                    
                                    3.3%
                                 | |
| 90 | 1 | 
                                    
                                    0.7%
                                 | |
| 100 | 11 | 
                                    
                                    7.3%
                                 |