Year	kt
1960	3909.022
1961	3542.322
1962	2009.516
1963	2306.543
1964	2559.566
1965	2603.57
1966	2588.902
1967	2940.934
1968	2368.882
1969	2592.569
1970	3289.299
1971	2929.933
1972	2860.26
1973	2882.262
1974	3369.973
1975	3597.327
1976	3241.628
1977	2706.246
1978	3835.682
1979	3604.661
1980	2867.594
1981	2959.269
1982	2662.242
1983	2192.866
1984	2148.862
1985	2775.919
1986	3395.642
1987	3780.677
1988	4026.366
1989	4147.377
1990	3072.946
1991	2691.578
1992	2805.255
1993	2302.876
1994	3564.324
1995	3703.67
1996	3102.282
1997	2779.586
1998	2841.925
1999	2156.196
2000	1657.484
2001	1290.784
2002	1100.1
2003	1991.181
2004	2200.2
2005	3270.964
2006	3868.685
2007	3663.333
2008	3879.686
2009	3234.294
2010	3993.363
2011	4726.763
2012	5012.789
2013	4235.385
2014	4176.713
2015	4008.031
2016	3010.607