```json
{
    "yes": [12.0, 18.0, 24.0, 36.0, 48.0],
    "no": [6.0, 9.0, 15.0, 30.0, 42.0]
}
```

Based on prior knowledge, we can analyze the relationship between the feature "duration" and the task of whether a person receives a credit or not. It is likely that the duration of an individual's credit can have an impact on the decision. People with shorter credit duration might have lower risk and higher chances of receiving credit, while individuals with longer credit durations might have higher risk and lower chances of receiving credit.

For the target class "yes" (person receives credit), we can consider some typical duration values such as 12 months, 18 months, 24 months, 36 months, and 48 months. These represent relatively shorter credit durations that are more likely associated with receiving credit.

For the target class "no" (person does not receive credit), we can consider some typical duration values such as 6 months, 9 months, 15 months, 30 months, and 42 months. These represent relatively longer credit durations that are more likely associated with not receiving credit.