Year	Percent change
1993	839.9
1994	215.1
1995	131.3
1996	21.8
1997	11
1998	84.4
1999	36.5
2000	20.2
2001	18.6
2002	15.1
2003	12
2004	11.7
2005	10.9
2006	9
2007	11.9
2008	13.3
2009	8.81
2010	8.78
2011	6.1
2012	6.57
2013	6.47
2014	11.35
2015	12.91
2016	5.367
2017	2.523
2018	4.269
2019	4.849
2020	4.164
2021	4.05
2022	4
2023	3.95
2024	4