Year	kt
1960	1393.46
1961	1452.132
1962	1507.137
1963	1653.817
1964	2405.552
1965	2082.856
1966	2416.553
1967	2475.225
1968	3006.94
1969	3215.959
1970	3094.948
1971	3670.667
1972	3986.029
1973	3997.03
1974	4220.717
1975	4422.402
1976	4807.437
1977	5639.846
1978	6068.885
1979	6912.295
1980	7425.675
1981	7568.688
1982	7425.675
1983	8643.119
1984	8144.407
1985	7972.058
1986	8782.465
1987	7223.99
1988	8459.769
1989	8122.405
1990	8808.134
1991	11257.69
1992	9955.905
1993	11338.364
1994	9684.547
1995	9009.819
1996	9992.575
1997	9904.567
1998	10432.615
1999	10315.271
2000	11224.687
2001	11521.714
2002	11452.041
2003	11668.394
2004	12170.773
2005	12321.12
2006	12335.788
2007	12233.112
2008	11980.089
2009	11562.051
2010	11507.046
2011	10780.98
2012	10832.318
2013	11397.036
2014	11862.745
2015	13582.568
2016	13193.866