Year	Percent change
1981	14.6
1982	12.7
1983	8.3
1984	6.5
1985	10.4
1986	10.8
1987	8.1
1988	10.4
1989	11.3
1990	12
1991	12.6
1992	16.5
1993	12.7
1994	9.8
1995	10.8
1996	9.6
1997	7.8
1998	6.365
1999	8.413
2000	8.48
2001	5.752
2002	10.6
2003	6.368
2004	7.89
2005	11.285
2006	8.522
2007	8.141
2008	13.678
2009	5.846
2010	7.41
2011	9.175
2012	7.435
2013	4.068
2014	3.75
2015	3.1
2016	2.986
2017	3.184
2018	3.539
2019	3.657
2020	3.8
2021	4
2022	3.95
2023	3.95
2024	3.95