When comparing the amount of raw crude oil and gold that R1 could buy in 1988 to February 2013, the R1 coins rolling off the mint in 2013 is only 5.7% of its former 1988 self.
Stated differently, the Rand has lost 94.3% of its value relative to oil and gold since 1988.
If you want to do the math yourself:
In 1988 an ounce of gold cost R1067. Today it costs R14,255.
In 1988 a barrel of crude oil cost R34. Today it costs R1,005.