It reveals two quite different lines. The bottom one is the relation between inflation and unemployment until the mid 70s. The top line is the relationship since then. Until the mid 70s unemployment was consistently low. Since the mid 70s a totally different relationship has prevailed.
High inflation is accompanied by low unemployment and vice versa.
From the pronouncements of our economic gurus you will probably have understood that we had to experience a period of pain to kill the demon of inflation and allow the country to return to an era of low inflation and low unemployment. In fact the graph shows we have not achieved any such structural change. All recent years, including 95 and 96, lie on the high line. Australia has been just sliding up and down that line. That is the current structure of the Australian economy.