Year	kt
1960	663.727
1961	869.079
1962	931.418
1963	1078.098
1964	1089.099
1965	1272.449
1966	1397.127
1967	1254.114
1968	1268.782
1969	1521.805
1970	1371.458
1971	1448.465
1972	1587.811
1973	1895.839
1974	1932.509
1975	2207.534
1976	2684.244
1977	2882.262
1978	3358.972
1979	3483.65
1980	4272.055
1981	5383.156
1982	5896.536
1983	6728.945
1984	7363.336
1985	7532.018
1986	8386.429
1987	8533.109
1988	8401.097
1989	8272.752
1990	9493.863
1991	9119.829
1992	10461.951
1993	10062.248
1994	11158.681
1995	11375.034
1996	12016.759
1997	12335.788
1998	12753.826
1999	12764.827
2000	13747.583
2001	13949.268
2002	14682.668
2003	15229.051
2004	14554.323
2005	15874.443
2006	14554.323
2007	14403.976
2008	12926.175
2009	12893.172
2010	13982.271
2011	18265.327
2012	20912.901
2013	19666.121
2014	22442.04
2015	19240.749
2016	14873.352