Year	kt
1960	953.42
1961	913.083
1962	1122.102
1963	1133.103
1964	1595.145
1965	1441.131
1966	1529.139
1967	1411.795
1968	2185.532
1969	2460.557
1970	2860.26
1971	3223.293
1972	4334.394
1973	5672.849
1974	6112.889
1975	6046.883
1976	6006.546
1977	5181.471
1978	5016.456
1979	6365.912
1980	5951.541
1981	5694.851
1982	5867.2
1983	7363.336
1984	6875.625
1985	6791.284
1986	7572.355
1987	8595.448
1988	8833.803
1989	8870.473
1990	8679.789
1991	9273.843
1992	9875.231
1993	10810.316
1994	11562.051
1995	14866.018
1996	16167.803
1997	16761.857
1998	16743.522
1999	16802.194
2000	18290.996
2001	17909.628
2002	19193.078
2003	16688.517
2004	14686.335
2005	15515.077
2006	15441.737
2007	16189.805
2008	15573.749
2009	15247.386
2010	15628.754
2011	15573.749
2012	15925.781
2013	14873.352
2014	14440.646
2015	16633.512
2016	17891.293