Year	kt
1960	2456.89
1961	2581.568
1962	1917.841
1963	2713.58
1964	2944.601
1965	3072.946
1966	3821.014
1967	3780.677
1968	4048.368
1969	4107.04
1970	5291.481
1971	6098.221
1972	5581.174
1973	7132.315
1974	8507.44
1975	8188.411
1976	8309.422
1977	9328.848
1978	9688.214
1979	12401.794
1980	12339.455
1981	12071.764
1982	13025.184
1983	13219.535
1984	13718.247
1985	13402.885
1986	12819.832
1987	13553.232
1988	14477.316
1989	15922.114
1990	16651.847
1991	16538.17
1992	18191.987
1993	19680.789
1994	20516.865
1995	20172.167
1996	19156.408
1997	19915.477
1998	19141.74
1999	20483.862
2000	19739.461
2001	19856.805
2002	19966.815
2003	20054.823
2004	24026.184
2005	25324.302
2006	25955.026
2007	27550.171
2008	30645.119
2009	30854.138
2010	34436.797
2011	36603.994
2012	37286.056
2013	37003.697
2014	34488.135
2015	34106.767
2016	34682.486