Year	kt
1990	54811.8
1991	47938.2
1992	46096.2
1993	44319.9
1994	41702
1995	42370.6
1996	42174.1
1997	42273.5
1998	41403.5
1999	40660.1
2000	38072.2
2001	38577
2002	38065.4
2003	38331.2
2004	37430.5
2005	38518.3
2006	37873.3
2007	37190.3
2008	37097.2
2009	33908.9
2010	35432.2
2011	34116.9
2012	32347.1
2013	32920.4
2014	30438.1
2015	30753.7
2016	31497.8
2017	33576.5
2018	33005.1
2019	31032.5
2020	29035.8