| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | when the [noun sg] | 3540 |
|
| 2 | 1991 the [noun sg] | 158 |
|
| 3 | 1991 when the | 17 |
|
| 4 | 1991 when [noun sg] | 5 |
|
