March 2006 futures represented 52% of total trading volume, while February 2006, April 2006 — June 2006, December 2006 accounted for 10%, 17%, 6%, 13% and 2% respectively.
On February 28, 2006 the open interest among March 2006 — September 2006 and December 2006 contracts was distributed as follows: 26%, 20%, 19%, 13%, 1%, 0,1%, 14%, 7%.