Year	kt
1960	-3.667
1961	-3.667
1962	-3.667
1963	-3.667
1964	-3.667
1965	0
1966	-3.667
1967	3.667
1968	22.002
1969	25.669
1970	84.341
1971	201.685
1972	256.69
1973	348.365
1974	737.067
1975	1184.441
1976	1239.446
1977	1415.462
1978	1554.808
1979	1738.158
1980	1983.847
1981	2141.528
1982	2262.539
1983	2486.226
1984	2772.252
1985	2904.264
1986	2973.937
1987	3186.623
1988	3208.625
1989	3490.984
1990	3736.673
1991	4195.048
1992	4411.401
1993	4627.754
1994	4561.748
1995	5027.457
1996	5441.828
1997	5254.811
1998	5408.825
1999	5603.176
2000	5573.84
2001	5801.194
2002	5694.851
2003	6017.547
2004	6208.231
2005	6373.246
2006	6197.23
2007	6035.882
2008	6428.251
2009	6171.561
2010	6893.96
2011	6112.889
2012	6703.276
2013	7058.975
2014	6116.556
2015	6530.927
2016	6864.624