Year	Percent change
1980	11.346
1981	12.654
1982	7.736
1983	12.558
1984	6.517
1985	6.251
1986	8.889
1987	9.059
1988	7.214
1989	4.569
1990	11.197
1991	13.483
1992	9.863
1993	7.279
1994	10.275
1995	9.962
1996	9.432
1997	6.842
1998	13.127
1999	5.698
2000	3.831
2001	4.311
2002	3.981
2003	3.864
2004	3.824
2005	4.404
2006	6.697
2007	6.204
2008	9.089
2009	12.314
2010	10.528
2011	9.5
2012	10
2013	9.4
2014	5.8
2015	4.9
2016	4.5
2017	3.602
2018	3.48
2019	3.882
2020	4.245
2021	4.232
2022	4.178
2023	4.086
2024	3.992