Year	kt
1960	689.396
1961	711.398
1962	1074.431
1963	1305.452
1964	1382.459
1965	1705.155
1966	2024.184
1967	2108.525
1968	2178.198
1969	2427.554
1970	2717.247
1971	3014.274
1972	3538.655
1973	3689.002
1974	3571.658
1975	3600.994
1976	3703.67
1977	4206.049
1978	5573.84
1979	5977.21
1980	6912.295
1981	7389.005
1982	7730.036
1983	8478.104
1984	8525.775
1985	7356.002
1986	6901.294
1987	7190.987
1988	7539.352
1989	7069.976
1990	8379.095
1991	8701.791
1992	8371.761
1993	8650.453
1994	8984.15
1995	8302.088
1996	10241.931
1997	12464.133
1998	13032.518
1999	11210.019
2000	12497.136
2001	13270.873
2002	13256.205
2003	12691.487
2004	13358.881
2005	14018.941
2006	14044.61
2007	14044.61
2008	17531.927
2009	20113.495
2010	22005.667
2011	21066.915
2012	22918.75
2013	23124.102
2014	22684.062
2015	23120.435
2016	21910.325