DemographicsPenna is approximately 29.43 square kilometres. In 2016 the population of Penna was 422. The population is 48% male and 52% female. On average the monthly mortgage repayments in Penna are $1000 to $1399. The most common weekly income bracket is $300 to $399 per week. Weekly rents in the area are on average $275 to $349.