How to add or remove Ethnicity values present under person demographic info

Summary:

1. Under Person details, we have ethnicity and race section where we have list of values to check. We have PER_ETHNICITY look up where these values are setup. However, when we try to disable any existing values or add any new values, it is not reflecting in the person details page. If these values are driven from this look up (User type lookup) why are we not able to add new values or remove existing.
2. Also, "Two or more races" and "Not disclosed" options are not seen in person details page both under ME and My client group navigations. But these two options are still present in the look up code PER_ETHNICITY with enabled status.