Pick List Bulk Option - from predefined choices

Pick List Bulk Option - from predefined choices

When I am editing a pick list properties there is an option under "add options in bulk"  to import from "Predefined Choices". I see four or five predefined choices (e.g. Days of the week, time zones, etc) How do I add my own predefined choices to this list (e.g. UK Counties, European regions, etc) ?