Year	kt
1960	612.389
1961	524.381
1962	542.716
1963	605.055
1964	726.066
1965	755.402
1966	755.402
1967	770.07
1968	788.405
1969	1301.785
1970	1261.448
1971	1430.13
1972	2427.554
1973	2665.909
1974	3039.943
1975	2618.238
1976	2328.545
1977	2335.879
1978	2537.564
1979	2409.219
1980	2434.888
1981	1928.842
1982	2999.606
1983	2753.917
1984	3274.631
1985	3428.645
1986	3582.659
1987	3655.999
1988	3707.337
1989	3058.278
1990	2695.245
1991	3846.683
1992	3388.308
1993	4136.376
1994	4176.713
1995	3912.689
1996	4092.372
1997	4198.715
1998	4888.111
1999	4979.786
2000	5331.818
2001	4143.71
2002	4668.091
2003	5192.472
2004	4998.121
2005	6090.887
2006	5988.211
2007	6582.265
2008	5863.533
2009	4396.733
2010	5452.829
2011	5317.15
2012	4132.709
2013	4121.708
2014	3593.66
2015	4305.058
2016	3454.314