| Value | Category | Cases | |
|---|---|---|---|
| 0 | NONE | 15593 | 
                                    
                                    93.8%
                                 | 
| 1 | 231 | 
                                    
                                    1.4%
                                 | |
| 2 | 305 | 
                                    
                                    1.8%
                                 | |
| 3 | 199 | 
                                    
                                    1.2%
                                 | |
| 4 | 103 | 
                                    
                                    0.6%
                                 | |
| 5 | 91 | 
                                    
                                    0.5%
                                 | |
| 6 | 26 | 
                                    
                                    0.2%
                                 | |
| 7 | 12 | 
                                    
                                    0.1%
                                 | |
| 8 | 8 | 
                                    
                                    0%
                                 | |
| 9 | 7 | 
                                    
                                    0%
                                 | |
| 10 | TEN OR MORE BOOKS | 47 | 
                                    
                                    0.3%
                                 | 
| 99 | NO RESPONSE | 2 | 
                                    
                                    0%
                                 | 
| Sysmiss | 65 |