Indonesian rupiah
The Indonesian rupiah only finally became legal tender in Irian on 18 February 1971. The existing Irian Barat money was exchangeable from May 1971 at the rate of 1 Irian Barat rupiah to 18.9 Indonesian rupiah. Thus given the official exchange rate of 378 Indonesian rupiah to 1 US$ at the time, it can be seen that the Irian Barat rupiah was ultimately worth exactly US$0.05. The Netherlands New Guinea gulden, fixed at par to the Dutch guilder, was exchangeable at 3.62 to the US dollar at the time of original conversion in 1963. Relative to the dollar therefore the currency had lost 82% of its value in 8 years.