| Value | Category | Cases | |
|---|---|---|---|
| 1 | Natural | 34001 |
84.4%
|
| 2 | Unnatural | 4722 |
11.7%
|
| 3 | Do not know | 843 |
2.1%
|
| 9 | Unspecified | 737 |
1.8%
|