Year	kt
1960	968.088
1961	931.418
1962	990.09
1963	1100.1
1964	1199.109
1965	1305.452
1966	1444.798
1967	1569.476
1968	1727.157
1969	1745.492
1970	1811.498
1971	1870.17
1972	2049.853
1973	2181.865
1974	2368.882
1975	2871.261
1976	3160.954
1977	3314.968
1978	3307.634
1979	3377.307
1980	3479.983
1981	3567.991
1982	3215.959
1983	3168.288
1984	3083.947
1985	3127.951
1986	2878.595
1987	2940.934
1988	2951.935
1989	3058.278
1990	3267.297
1991	3285.632
1992	3410.31
1993	3700.003
1994	4176.713
1995	5027.457
1996	5478.498
1997	5793.86
1998	6600.6
1999	6039.549
2000	4664.424
2001	5082.462
2002	4932.115
2003	6057.884
2004	6094.554
2005	6706.943
2006	6618.935
2007	7176.319
2008	7308.331
2009	7429.342
2010	7876.716
2011	8346.092
2012	10252.932
2013	10091.584
2014	10623.299
2015	10124.587
2016	10773.646