The initial ISO 4217 code was ZWD. At the time of its introduction, the Zimbabwean dollar was worth more than the US dollar in the official exchange market, with 1 ZWD = US$1.47, although this did not reflect the actual purchasing power it held. As a result, in both the official and parallel markets, the currency's value eroded rapidly over the years, and by July 2006, the parallel market value of the Zimbabwean dollar fell to Z$1,000,000 = GBP £1.[12]