| Value | Category | 
|---|---|
| 1 | Up to three months ago | 
| 2 | Between three and six months ago | 
| 3 | Between 6 months and a year ago | 
| 4 | Over a year ago, but less than 2 years ago | 
| 5 | 2 years or more ago but less than 5 years ago | 
| 6 | 5 years ago or more | 
| 7 | Don?t know/Can?t remember (DON?T READ) | 
| Sysmiss |