Year kt 1992 44451.374 1993 36699.336 1994 30509.44 1995 28532.927 1996 26637.088 1997 22889.414 1998 22068.006 1999 19816.468 2000 16699.518 2001 15797.436 2002 14983.362 2003 14620.329 2004 16450.162 2005 16530.836 2006 18518.35 2007 16666.515 2008 18441.343 2009 23325.787 2010 16941.54 2011 20091.493 2012 18881.383 2013 18312.998 2014 18004.97 2015 16772.858 2016 16835.197