Year	kt
1960	744.401
1961	722.399
1962	722.399
1963	766.403
1964	821.408
1965	1602.479
1966	1624.481
1967	616.056
1968	-179.683
1969	388.702
1970	1188.108
1971	1232.112
1972	1287.117
1973	1404.461
1974	1686.82
1975	2401.885
1976	1584.144
1977	2079.189
1978	2449.556
1979	2709.913
1980	3157.287
1981	3109.616
1982	2874.928
1983	2434.888
1984	3116.95
1985	2475.225
1986	2478.892
1987	2266.206
1988	2533.897
1989	3490.984
1990	2937.267
1991	3168.288
1992	3175.622
1993	3274.631
1994	3520.32
1995	3058.278
1996	3252.629
1997	2790.587
1998	2893.263
1999	3190.29
2000	3270.964
2001	3560.657
2002	3410.31
2003	3828.348
2004	3644.998
2005	4107.04
2006	2823.59
2007	2878.595
2008	2937.267
2009	2291.875
2010	4994.454
2011	5053.126
2012	4701.094
2013	4935.782
2014	5731.521
2015	6864.624
2016	6831.621