Year	kt
1960	67960.511
1961	67043.761
1962	68598.569
1963	71341.485
1964	65074.582
1965	61887.959
1966	58239.294
1967	56919.174
1968	58514.319
1969	55932.751
1970	49038.791
1971	40439.676
1972	42163.166
1973	45276.449
1974	48496.075
1975	38510.834
1976	41297.754
1977	38862.866
1978	43684.971
1979	47142.952
1980	47194.29
1981	46248.204
1982	45668.818
1983	36662.666
1984	42042.155
1985	40744.037
1986	36090.614
1987	36482.983
1988	33153.347
1989	40098.645
1990	38250.477
1991	36182.289
1992	33630.057
1993	30439.767
1994	32724.308
1995	31382.186
1996	30296.754
1997	29189.32
1998	29596.357
1999	25837.682
2000	29086.644
2001	26651.756
2002	23274.449
2003	21906.658
2004	21026.578
2005	18657.696
2006	17971.967
2007	16046.792
2008	16281.48
2009	11316.362
2010	13886.929
2011	12915.174
2012	11752.735
2013	12394.46
2014	11804.073
2015	11481.377
2016	10557.293