Year	kt
1960	6684.941
1961	7198.321
1962	7711.701
1963	8221.414
1964	7711.701
1965	7198.321
1966	6424.584
1967	7964.724
1968	7964.724
1969	8522.108
1970	5812.195
1971	6505.258
1972	6695.942
1973	7774.04
1974	8316.756
1975	8786.132
1976	9226.172
1977	9420.523
1978	9904.567
1979	11265.024
1980	10307.937
1981	10670.97
1982	10997.333
1983	12148.771
1984	12005.758
1985	12218.444
1986	12049.762
1987	12475.134
1988	12559.475
1989	12977.513
1990	13894.263
1991	12423.796
1992	13677.91
1993	14216.959
1994	13622.905
1995	14147.286
1996	12522.805
1997	12299.118
1998	11697.73
1999	9691.881
2000	10234.597
2001	10329.939
2002	9273.843
2003	10414.28
2004	7286.329
2005	10241.931
2006	9358.184
2007	8060.066
2008	10777.313
2009	11811.407
2010	13483.559
2011	13795.254
2012	11551.05
2013	13131.527
2014	14623.996
2015	19160.075
2016	19471.77