According to the media release by Phillip Lowe, "The unemployment rate is expected to decline gradually over time." Suppose that Australia has an adult population of 50 million and a participation rate of 60%. The ABS uses the rule that anyone doing 1 hour's paid work or more is counted as employed. On this basis, suppose that it finds Australia has 27 million employed people.

What is Australia's official unemployment rate? Round your answer to a whole number. ( )%