Year	kt
1960	575.719
1961	546.383
1962	616.056
1963	1085.432
1964	1188.108
1965	1001.091
1966	1235.779
1967	1089.099
1968	1184.441
1969	1122.102
1970	1349.456
1971	1419.129
1972	1569.476
1973	1848.168
1974	1826.166
1975	1943.51
1976	2049.853
1977	2101.191
1978	2163.53
1979	2097.524
1980	1873.837
1981	1606.146
1982	1558.475
1983	1686.82
1984	1408.128
1985	1763.827
1986	1771.161
1987	2145.195
1988	2159.863
1989	2273.54
1990	2200.2
1991	2863.927
1992	3138.952
1993	3604.661
1994	4147.377
1995	4616.753
1996	4008.031
1997	4979.786
1998	5276.813
1999	5148.468
2000	5218.141
2001	5364.821
2002	5518.835
2003	5856.199
2004	5731.521
2005	5837.864
2006	6186.229
2007	6329.242
2008	5892.869
2009	5837.864
2010	5815.862
2011	5988.211
2012	5973.543
2013	5632.512
2014	5786.526
2015	6351.244
2016	6670.273