Year Tonnes 1928 3667 1929 7334 1930 14668 1931 18335 1932 22002 1933 25669 1934 29336 1935 29336 1936 29336 1937 29336 1938 29336 1939 33003 1940 33003 1941 33003 1942 33003 1943 33003 1944 33003 1945 33003 1946 33003 1947 36670 1948 40337 1949 44004 1950 117344 1951 227354 1952 315362 1953 425372 1954 539049 1955 667394 1956 795739 1957 931418 1958 1081765 1959 1232112 1960 1404461 1961 1598812 1962 1859169 1963 2049853 1964 2229536 1965 2434888 1966 2702579 1967 3039943 1968 3479983 1969 3960360 1970 4389399 1971 4873443 1972 5375822 1973 5856199 1974 6347577 1975 6915962 1976 7447677 1977 8038064 1978 8668788 1979 9270176 1980 9944904 1981 10630633 1982 11276025 1983 11961754 1984 12709822 1985 13556899 1986 14473649 1987 15416068 1988 16362154 1989 17352244 1990 18426675 1991 19633118 1992 20612207 1993 21726975 1994 22475043 1995 23303785 1996 24154529 1997 25056611 1998 26197048 1999 27407158 2000 28595266 2001 29816377 2002 31044822 2003 32313604 2004 33608055 2005 34961178 2006 36332636 2007 37696760 2008 39317574 2009 40934721 2010 42412522 2011 43941661 2012 45412128 2013 46860593 2014 48133042