Even with such low mileage per year, I'd change the oil at least once a year: if you put the vehicle into winter hibernation, change the oil before hibernation, running the engine to a steady temperature after the oil change.
If you do a lot of short-distance driving, change oil twice a year/driving-season.
In case it matters, my good friends call me Bubba and my really good friends call me screwball. Yet, they find it impressive that I have a 1954 truck with a strong engine in it that was rebuilt (by me - my second rebuild) in 1972.
Call the technical department of an oil company (as a person, not a professional) and, if you get through to a human being, they will most likely have an inexperienced person read to you from a technical manual (hope they are reading the entry in the manual that relates to your situation).
