Year	kt
1960	348.365
1961	311.695
1962	1008.425
1963	1034.094
1964	1041.428
1965	1012.092
1966	1334.788
1967	799.406
1968	1419.129
1969	2500.894
1970	1745.492
1971	1646.483
1972	2478.892
1973	2511.895
1974	2453.223
1975	2181.865
1976	1936.176
1977	1074.431
1978	2680.577
1979	2772.252
1980	2658.575
1981	2764.918
1982	2159.863
1983	2537.564
1984	2291.875
1985	1961.845
1986	1870.17
1987	2926.266
1988	1906.84
1989	1745.492
1990	2478.892
1991	2284.541
1992	2291.875
1993	2970.27
1994	1298.118
1995	8423.099
1996	7044.307
1997	3333.303
1998	2764.918
1999	3711.004
2000	3670.667
2001	4305.058
2002	5023.79
2003	6842.622
2004	5038.458
2005	4737.764
2006	7763.039
2007	8808.134
2008	10227.263
2009	12306.452
2010	13380.883
2011	14356.305
2012	17282.571
2013	17454.92
2014	28265.236
2015	17080.886
2016	17931.63