Year	kt
1960	326.363
1961	322.696
1962	363.033
1963	282.359
1964	333.697
1965	396.036
1966	476.71
1967	524.381
1968	590.387
1969	689.396
1970	891.081
1971	990.09
1972	1081.765
1973	1169.773
1974	1210.11
1975	1261.448
1976	1272.449
1977	1701.488
1978	2126.86
1979	2684.244
1980	2324.878
1981	2647.574
1982	2882.262
1983	3105.949
1984	3402.976
1985	3725.672
1986	3711.004
1987	3736.673
1988	4019.032
1989	4059.369
1990	2500.894
1991	1481.468
1992	799.406
1993	601.388
1994	168.682
1995	161.348
1996	113.677
1997	44.004
1998	55.005
1999	110.01
2000	69.673
2001	80.674
2002	84.341
2003	84.341
2004	84.341
2005	73.34
2006	73.34
2007	73.34
2008	102.676
2009	388.702
2010	429.039
2011	535.382
2012	627.057
2013	550.05
2014	700.397
2015	227.354
2016	14.668