Year	kt
1960	2141.528
1961	2244.204
1962	2420.22
1963	2559.566
1964	2797.921
1965	2808.922
1966	3072.946
1967	3061.945
1968	3234.294
1969	3703.67
1970	3274.631
1971	4580.083
1972	4873.443
1973	6307.24
1974	6336.576
1975	5581.174
1976	5262.145
1977	4880.777
1978	5009.122
1979	5082.462
1980	5423.493
1981	5144.801
1982	5258.478
1983	6571.264
1984	6428.251
1985	7557.687
1986	7308.331
1987	7517.35
1988	7209.322
1989	7601.691
1990	7766.706
1991	8030.73
1992	9611.207
1993	9893.566
1994	10685.638
1995	11312.695
1996	11415.371
1997	13688.911
1998	14462.648
1999	14601.994
2000	13344.213
2001	14227.96
2002	14077.613
2003	15738.764
2004	14103.282
2005	13410.219
2006	12291.784
2007	10989.999
2008	14605.661
2009	17836.288
2010	16391.49
2011	17073.552
2012	19358.093
2013	19171.076
2014	20692.881
2015	21052.247
2016	21459.284