Full or interim service with my next MOT?

I have a 2012 semi-automatic Peugeot 308 (diesel).

I bought it a year ago (it was MOT'd when I bought it and passed fine).

This is the basic history:

12/2012 - Service - 950 miles
10/2013 - Service - 8,300 miles
10/2015 - MOT - 27,700 miles
01/2016 - MOT/Service - 28,700 miles
07/2016 - Service - 38,000 miles
01/2017 - Service - 46,500 miles
05/2017 - MOT - 46,500 miles

I'm now on roughly 51,000 miles.

As I only do 4,500 miles per year, should I go for a full service when my MOT is due in May, or just an interim one?