Based on prior knowledge, the duration feature is likely to have a relationship with the target variable. Shorter durations may indicate a higher probability of receiving a credit, while longer durations may indicate a lower probability.

Here is the generated dictionary:

```json
{
	"yes": [6.0, 9.0, 12.0, 15.0, 18.0],
	"no": [21.0, 24.0, 27.0, 30.0, 33.0]
}
```

This dictionary suggests that for the target class "yes" (person receives credit), typical duration values are around 6, 9, 12, 15, and 18 months. On the other hand, for the target class "no" (person does not receive credit), typical duration values are around 21, 24, 27, 30, and 33 months.