| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1. Currently and regularly implemented | 18 |
5.8%
|
| 2 | 2. Still implemented,but not routine | 2 |
0.6%
|
| 3 | 3. Conducted once but no longer implemented | 13 |
4.2%
|
| 4 | 4. Never conducted | 277 |
89.4%
|
| 9 | 9. Missing | 0 |
0%
|