DemographicsSt Aubyn is approximately 13.94 square kilometres. In 2016 the population of St Aubyn was 8. The population is 33% male and 67% female. On average the monthly mortgage repayments in St Aubyn are $0 to $299. The most common weekly income bracket is $400 to $499 per week. Weekly rents in the area are on average $0 to $74.