The size of Arnold is approximately 18,236.2 square kilometres. The population of Arnold in 2011 was 195 people. By 2016 the population was 15 showing a population decline of 92.3% in the area during that time. The predominant age group in Arnold is 0-9 years. Households in Arnold are primarily childless couples and are likely to be repaying under $300 per month on mortgage repayments. In general, people in Arnold work in a clerical occupation. In 2006, 31.6% of the homes in Arnold were owner-occupied compared with 54.9% in 2011.