The size of Derby is approximately 162.4 square kilometres. It has 4 parks covering nearly 0.6% of total area. The population of Derby in 2011 was 4,865 people. By 2016 the population was 3,523 showing a population decline of 27.6% in the area during that time. The predominant age group in Derby is 0-9 years. Households in Derby are primarily couples with children and are likely to be repaying $1400 - $1799 per month on mortgage repayments. In general, people in Derby work in a professional occupation. In 2011, 36.1% of the homes in Derby were owner-occupied compared with 27.1% in 2016. Currently the median sales price of houses in the area is $252,500.