Year	kt
1960	605.055
1961	1096.433
1962	1030.427
1963	1441.131
1964	656.393
1965	997.424
1966	2629.239
1967	2445.889
1968	2966.603
1969	6446.586
1970	2849.259
1971	2636.573
1972	3197.624
1973	4198.715
1974	4734.097
1975	5471.164
1976	9160.166
1977	10828.651
1978	9952.238
1979	13080.189
1980	14209.625
1981	19391.096
1982	21796.648
1983	20472.861
1984	17597.933
1985	20315.18
1986	17619.935
1987	19035.397
1988	21719.641
1989	20923.902
1990	18921.72
1991	25305.967
1992	22948.086
1993	25551.656
1994	29629.36
1995	31906.567
1996	29123.314
1997	29948.389
1998	31118.162
1999	32625.299
2000	33457.708
2001	33901.415
2002	33146.013
2003	34271.782
2004	33956.42
2005	34282.783
2006	32826.984
2007	29644.028
2008	33094.675
2009	37212.716
2010	38558.505
2011	25272.964
2012	33417.371
2013	35734.915
2014	36248.295
2015	33212.019
2016	29864.048