| Value | Category | Cases | |
|---|---|---|---|
| 1 | textbook | 31 |
79.5%
|
| 2 | multimedia | 2 |
5.1%
|
| 3 | workbook | 2 |
5.1%
|
| 4 | 4 |
10.3%
|
|
| Sysmiss | 11 |