Year	kt
1960	20784.556
1961	23307.452
1962	27058.793
1963	32027.578
1964	35599.236
1965	40513.016
1966	43879.322
1967	46724.914
1968	54784.98
1969	59603.418
1970	65382.61
1971	66805.406
1972	71524.835
1973	73692.032
1974	63827.802
1975	61488.256
1976	65037.912
1977	64150.498
1978	68873.594
1979	67916.507
1980	63967.148
1981	55613.722
1982	53189.835
1983	45808.164
1984	43706.973
1985	44183.683
1986	50421.25
1987	48683.092
1988	49075.461
1989	47436.312
1990	45635.815
1991	51187.653
1992	53585.871
1993	51873.382
1994	53263.175
1995	52544.443
1996	56779.828
1997	56336.121
1998	56717.489
1999	54253.265
2000	51847.713
2001	54121.253
2002	49918.871
2003	54755.644
2004	53358.517
2005	52335.424
2006	50655.938
2007	48529.078
2008	50831.954
2009	50494.59
2010	54979.331
2011	50600.933
2012	47318.968
2013	48881.11
2014	49662.181
2015	52683.789
2016	50446.919