Year	kt
1960	7400.006
1961	7788.708
1962	9090.493
1963	9402.188
1964	10861.654
1965	10535.291
1966	11697.73
1967	12090.099
1968	12838.167
1969	13281.874
1970	14411.31
1971	15408.734
1972	14913.689
1973	15863.442
1974	17403.582
1975	18173.652
1976	18573.355
1977	19402.097
1978	18742.037
1979	18569.688
1980	20714.883
1981	20249.174
1982	20087.826
1983	17575.931
1984	17821.62
1985	16413.492
1986	18364.336
1987	22137.679
1988	21239.264
1989	18569.688
1990	17744.613
1991	16703.185
1992	17062.551
1993	19457.102
1994	19064.733
1995	19647.786
1996	20131.83
1997	23278.116
1998	23083.765
1999	24568.9
2000	23182.774
2001	20201.503
2002	19380.095
2003	18459.678
2004	20714.883
2005	20967.906
2006	18742.037
2007	22519.047
2008	21440.949
2009	23685.153
2010	23212.11
2011	23930.842
2012	25716.671
2013	26024.699
2014	25995.363
2015	27832.53
2016	31928.569