| Value | Category | Cases | |
|---|---|---|---|
| -99 | NA | 3522 |
75.3%
|
| -98 | 4 |
0.1%
|
|
| -97 | Refused | 97 |
2.1%
|
| 1 | More comfortable | 310 |
6.6%
|
| 2 | Less comfortable | 493 |
10.5%
|
| 3 | No difference whether smoking or not | 249 |
5.3%
|