Year	kt
1960	11129.345
1961	12610.813
1962	16043.125
1963	19908.143
1964	20835.894
1965	23930.842
1966	25804.679
1967	27722.52
1968	31437.191
1969	33494.378
1970	35661.575
1971	37674.758
1972	38565.839
1973	41807.467
1974	37080.704
1975	35261.872
1976	36739.673
1977	36904.688
1978	37938.782
1979	35324.211
1980	35144.528
1981	32632.633
1982	30454.435
1983	33589.72
1984	32309.937
1985	32797.648
1986	35412.219
1987	33153.347
1988	33641.058
1989	31869.897
1990	34917.174
1991	35019.85
1992	35452.556
1993	33457.708
1994	33901.415
1995	31470.194
1996	32082.583
1997	34011.425
1998	34150.771
1999	32958.996
2000	31132.83
2001	34664.151
2002	32683.971
2003	31862.563
2004	31825.893
2005	32511.622
2006	33230.354
2007	29431.342
2008	31440.858
2009	32973.664
2010	29438.676
2011	28184.562
2012	28477.922
2013	30531.442
2014	26629.754
2015	26450.071
2016	24884.262