Year	Percent change
1980	18.017
1981	12.244
1982	9.481
1983	11.787
1984	10.339
1985	4.731
1986	5.828
1987	9.273
1988	8.044
1989	6.418
1990	7.843
1991	9.369
1992	7.506
1993	9.688
1994	8.518
1995	9.432
1996	8.379
1997	6.194
1998	58.02
1999	20.75
2000	3.773
2001	11.502
2002	11.78
2003	6.773
2004	6.062
2005	10.459
2006	13.104
2007	6.662
2008	9.777
2009	5.047
2010	5.14
2011	5.344
2012	3.981
2013	6.413
2014	6.395
2015	6.363
2016	3.526
2017	3.809
2018	3.198
2019	3.344
2020	3.554
2021	3.312
2022	3.062
2023	2.996
2024	2.991