Year	kt
1960	14888.02
1961	14469.982
1962	15903.779
1963	16131.133
1964	14921.023
1965	13732.915
1966	14070.279
1967	12577.81
1968	12343.122
1969	11507.046
1970	9365.518
1971	5742.522
1972	5331.818
1973	9075.825
1974	8188.411
1975	10839.652
1976	12247.78
1977	13740.249
1978	12882.171
1979	16303.482
1980	22035.003
1981	18103.979
1982	22082.674
1983	19981.483
1984	21382.277
1985	28026.881
1986	27033.124
1987	27491.499
1988	25988.029
1989	20513.198
1990	23010.425
1991	31572.87
1992	25691.002
1993	27663.848
1994	29552.353
1995	23795.163
1996	34579.81
1997	24477.225
1998	22009.334
1999	17799.618
2000	15207.049
2001	15973.452
2002	16120.132
2003	21503.288
2004	16435.494
2005	14198.624
2006	20971.573
2007	17550.262
2008	15196.048
2009	15185.047
2010	14447.98
2011	12269.782
2012	9361.851
2013	11437.373
2014	9134.497
2015	6549.262
2016	7187.32