Year	Tonnes
1928	33003
1929	62339
1930	84341
1931	106343
1932	121011
1933	135679
1934	150347
1935	168682
1936	194351
1937	227354
1938	267691
1939	304361
1992	24183865
1993	43692305
1994	62735036
1995	80255962
1996	98605630
1997	116713276
1998	133024092
1999	148183470
2000	163042154
2001	178612236
2002	193500256
2003	210625146
2004	227907717
2005	244662240
2006	260837377
2007	279546411
2008	297038001
2009	311603325
2010	329710971
2011	348317329
2012	365940931
2013	385834406
2014	405353847