| Value | Category | Cases | |
|---|---|---|---|
| -1 | Don't know | 0 |
0%
|
| 1 | Less than 1 year | 34 |
3.3%
|
| 2 | 1 to 5 years | 151 |
14.9%
|
| 3 | More than 5 years | 830 |
81.8%
|