| Value | Category | Cases | |
|---|---|---|---|
| 1 | General purpose | 0 | 
                                    
                                    0%
                                 | 
| 2 | Instructional materials | 10 | 
                                    
                                    100%
                                 | 
| 3 | Not specified | 0 | 
                                    
                                    0%
                                 | 
| 9 | Other (specify) | 0 | 
                                    
                                    0%
                                 | 
| 99 | NA | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 1957 |