This FACT indicates the percentage of the population who have completed year 12 or equivalent. While it is compulsory for children to attend school from the ages 5 to 15, and in some cases 17, it is not compulsory to complete high school after these ages. The age at which you can leave school varies from state to state. Because of this, Australia does not have very high year 12 completion rates. Many students choose to end their high school education in order to pursue career paths and options that do not require the completion of year 12 studies or their equivalent.