| Value | Category | Cases | |
|---|---|---|---|
| -9 | do not know | 18 |
12.2%
|
| 1 | less than one year | 33 |
22.3%
|
| 2 | 41 |
27.7%
|
|
| 3 | 23 |
15.5%
|
|
| 4 | 15 |
10.1%
|
|
| 5 | 6 |
4.1%
|
|
| 7 | 3 |
2%
|
|
| 10 | 3 |
2%
|
|
| 12 | 1 |
0.7%
|
|
| 13 | 1 |
0.7%
|
|
| 14 | 2 |
1.4%
|
|
| 30 | 1 |
0.7%
|
|
| 54 | 1 |
0.7%
|