Oiled currency

The American Geological Institute just published an interesting statistics, detailed in this pdf.
The price of a barrel of oil has stayed steady to the ounce of gold since 2001. Whereas the price of oil to the dollar has risen even faster than compared to the euro.
What baffles me, is that oil is usually perceived as a scarce and finite resource. Demand for oil has risen fast in the last 7 years, and supply not risen significantly.
Whereas demand for gold has risen a modest 3% per year since 2001 while the production has dropped a little.
The gap between dollar and euro as a result of the weakening dollar is widening - further speeding this process.