Year	kt
1990	21284042.79
1991	21440490.2
1992	21390040.84
1993	21531833.41
1994	21676894.94
1995	22299203.28
1996	22778983.29
1997	23202623.39
1998	23365547.83
1999	23530421.41
2000	24280271.96
2001	24644437.95
2002	24989512.93
2003	26133423.08
2004	27331852.94
2005	28371817.05
2006	29308175.54
2007	30418994.07
2008	30632298.65
2009	30238050.03
2010	32095872.94
2011	33079721.35
2012	33460087.5
2013	34119894.39
2014	34261369.66
2015	34070176.85
2016	34145652.3
2017	34687837.09
2018	35560555.79
2019	35477245.4
2020	33566427.59