Year	kt
1990	171.9
1991	173.1
1992	177.6
1993	185.2
1994	183.6
1995	185
1996	177
1997	197.3
1998	172.4
1999	191.6
2000	147
2001	148.2
2002	153.6
2003	195.1
2004	205.4
2005	209.5
2006	216.7
2007	229.9
2008	223.6
2009	234.6
2010	241
2011	243.5
2012	246
2013	247.4
2014	263.6
2015	281.9
2016	305
2017	306.6
2018	317.8
2019	325.3
2020	329