Table
| Extension | 0..* | |
| Extension.id | string | 0..1 |
| Extension.extension | Extension | 0..* |
| Extension.url | uri | 1..1 |
| Extension.value[x]:valueDuration | Duration | 0..1 |
| Extension.value[x]:valueDuration.id | string | 0..1 |
| Extension.value[x]:valueDuration.extension | Extension | 0..* |
| Extension.value[x]:valueDuration.value | decimal | 0..1 |
| Extension.value[x]:valueDuration.comparator | code | 0..0 |
| Extension.value[x]:valueDuration.unit | string | 0..1 |
| Extension.value[x]:valueDuration.system | uri | 0..1 |
| Extension.value[x]:valueDuration.code | code | 0..1 |