| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | of [num] years [unc] duration | 52 |
|
| 2 | of [adj] years ' duration | 52 |
|
| 3 | of [adj] years ['s] duration | 52 |
|
| 4 | of [adj] years [unc] duration | 52 |
|
| 5 | of [adj] years ' duration | 52 |
|
| 6 | of three years [unc] duration | 25 |
|
| 7 | of three years [unc] duration | 25 |
|
| 8 | of four years [unc] duration | 18 |
|
| 9 | of four years [unc] duration | 18 |
|
| 10 | of two years [unc] duration | 7 |
|
| 11 | of two years [unc] duration | 7 |
|
