Year Tonnes 1986 179683 1987 627057 1988 1239446 1989 1888505 1990 3527654 1991 5210807 1992 6673940 1993 8269085 1994 9882565 1995 11551050 1996 13241537 1997 14987029 1998 16783859 1999 18591690 2000 20971573 2001 23380792 2002 25819347 2003 28382580 2004 31000818 2005 33721732 2006 36438979 2007 39262569 2008 41921144 2009 44550383 2010 47058611 2011 49559505 2012 50908961 2013 51770706 2014 52643452