The price plot on the top half of the charts shows the intraday average for the last 4 years - a 1 minute tick 24 hours a day from March 2006 to March 2010. Approximately 1000 days all averaged so as to find any impositions on the price plot. Further below you can see the individual months & years laid out.
Here you can see many random months where the markets can be rising, steady or falling but through all the clutter are the outstanding slides on each of the London fixes. These are the times when the greatest manipulation takes place. Gold is now traded around the clock on electronic trading as well as open outcry. Demand is active all hours of the day across the globe.
Of note is that the active manipulation at 10:00am NYT coinciding with the London Fix (3:00pm GMT) is the same as seen here in an earlier study.
The bottom half of the plot shows the countries with trading exchanges that settle their futures contracts in physical as well as cash. These trading exchanges are the world's major trading exchanges that add to price discovery around the clock. They trade in volume & delivery to such an extent that they add to the price discovery that goes on 24 hours a day around the globe. There are plenty of other exchanges offering cash settlement only futures but generally their volumes are low & it's likely that most of these exchanges add little to the price discovery. Singapore, Sydney & Zurich have all stopped trading gold futures & now deal OTC for clients and as such are no longer included as they don't offer price discovery.