| Value | Category | Cases | |
|---|---|---|---|
| 1 | Up to six months ago | 1 |
0.4%
|
| 2 | Over 6 months ago but up to one year ago | 7 |
3.1%
|
| 3 | Over a year ago, but less than 2 years ago | 7 |
3.1%
|
| 4 | 2 years or more ago but less than 5 years ago | 24 |
10.5%
|
| 5 | 5 years ago, or more | 176 |
77.2%
|
| 99 | Don?t know/can?t remember | 13 |
5.7%
|
| Sysmiss | 13766 |