The rate of incarceration in Australia between 1984-2016

Over the past three decades, Australia has seen close to 140% increase in its rate of incarceration, from 86 per 100,000 in 1984 to 206 per 100,000 in 2016.
Much like the United States, the United Kingdom, and New Zealand, this rise in incarceration has continued in the face of stable or declining crime rates, such that the increase in incarceration rates cannot be simply explained as a reflection of increasing crime rates.
Reflecting on this massive rise in incarceration, write an essay that addresses the following questions:
In your estimation, what are the primary factors or “drivers” in the growth of imprisonment during this time?