Year	Percent change
1980	18.2
1981	20.056
1982	10.807
1983	11.568
1984	12.94
1985	20.463
1986	13.737
1987	13.377
1988	20.395
1989	7.546
1990	13.092
1991	8.934
1992	7.558
1993	12.023
1994	13.769
1995	12.289
1996	6.425
1997	7.125
1998	8.11
1999	6.089
2000	12.209
2001	5.942
2002	12.02
2003	7.29
2004	3.445
2005	4.898
2006	5.2
2007	8.076
2008	12.657
2009	7.448
2010	4.509
2011	6.107
2012	8.94
2013	5.621
2014	5.68
2015	4.952
2016	7.847
2017	6.221
2018	4.825
2019	5.626
2020	5.52
2021	5.472
2022	5.473
2023	5.536
2024	5.511