Gold: Supply and Demand

Just a note to myself. Eric Sprott has got supply and demand numbers for gold out:
http://kingworldnews.com/kingworldnews/KWN_DailyWeb/Entries/2012/8/24_Sprott_-_We_Are_Staring_At_Chaos_%26_Collapse_In_Front_Of_Us.html

Gold Supply = 4000 tons/annum
Gold Demand = 6500 tons/annum
Gold Lease = 2500 tons/annum

We'll just have to find out what these numbers mean...