chart, page-23

The international price of gold is in US dollars but a US dollar is NOT a US dollar is NOT a US dollar. The US dollar has lost a considerable amount of purchasing power over the last decade. One US dollar today is worth considerably less than one US dollar 10 years ago.

So how about adjusting that suggested "38.2% retrace of the last decade" for gold by also allowing for cumulative real US inflation figures "over the last decade" which of course also means ignoring the official downramped US inflation figures and making use of information from a "keep the US Government honest" site such as shadowstats.com