1988 was a whole different world. Before 2001, there was no such thing as spot retail forex trading on the AUDNZD . The high they are referring to was way back when it was only a futures market. It was not the same market, and once spot retail trading became available, it totally changed the complexion of the market.
I sure hope it doesn't go up more. At least not until I can get some more funds in there to cover my stupid strategy.