How to get list of possible values for Contact Types - for one Infusionsoft account?

Using the API (DataService), I need to get this list here:

Looking up in the Table Schema but nothing shows up regarding Contact Type.
Although I CAN get a Contact Type from EACH Contact. But what we need is to know ALL the possible values of Contact Type - including the ones recently created by any user.

Is there something else in the Table Schema that I may have overlooked? Or is there a separate function to get one?

Query the LinkedContactType table: