The size of Munni is approximately 54.7 square kilometres. The population of Munni in 2011 was 279 people. By 2016 the population was 21 showing a population decline of 92.5% in the area during that time. The predominant age group in Munni is 60-69 years. Households in Munni are primarily childless couples and are likely to be repaying over $4000 per month on mortgage repayments. In general, people in Munni work in a managers occupation. In 2006, 32.1% of the homes in Munni were owner-occupied compared with 69.2% in 2011.