| Value | Category | Cases | |
|---|---|---|---|
| 0 | NONE | 520 | 
                                    
                                    33.2%
                                 | 
| 1 | ONE | 58 | 
                                    
                                    3.7%
                                 | 
| 2 | TWO | 80 | 
                                    
                                    5.1%
                                 | 
| 3 | THREE | 80 | 
                                    
                                    5.1%
                                 | 
| 4 | FOUR | 74 | 
                                    
                                    4.7%
                                 | 
| 5 | FIVE | 69 | 
                                    
                                    4.4%
                                 | 
| 6 | SIX | 54 | 
                                    
                                    3.5%
                                 | 
| 7 | SEVEN | 56 | 
                                    
                                    3.6%
                                 | 
| 8 | EIGHT | 18 | 
                                    
                                    1.2%
                                 | 
| 9 | NINE | 13 | 
                                    
                                    0.8%
                                 | 
| 10 | TEN OR MORE BOOKS | 484 | 
                                    
                                    30.9%
                                 | 
| Sysmiss | 58 | 
                                    
                                    3.7%
                                 |