| Value | Category | Cases | |
|---|---|---|---|
| 1 | Twice or more per month | 31 | 
                                                                 
                                    
                                    11.4%
                                 
                                                             | 
                                                        
                    
| 2 | Monthly | 21 | 
                                                                 
                                    
                                    7.7%
                                 
                                                             | 
                                                        
                    
| 3 | Quarterly | 26 | 
                                                                 
                                    
                                    9.6%
                                 
                                                             | 
                                                        
                    
| 4 | Semi-annually | 51 | 
                                                                 
                                    
                                    18.8%
                                 
                                                             | 
                                                        
                    
| 5 | Annually | 17 | 
                                                                 
                                    
                                    6.3%
                                 
                                                             | 
                                                        
                    
| 6 | Sporadically as needed | 123 | 
                                                                 
                                    
                                    45.4%
                                 
                                                             | 
                                                        
                    
| 7 | Other (specify) | 2 | 
                                                                 
                                    
                                    0.7%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 2163 |