| Value | Category | Cases | |
|---|---|---|---|
| 1 | Flat | 236 |
28.3%
|
| 2 | Slight slope | 483 |
57.9%
|
| 3 | Steep slope | 114 |
13.7%
|
| d | 1 |
0.1%
|
|
| Sysmiss | 91 |