Year	Percent change
1980	20.627
1981	24.199
1982	18.681
1983	19.742
1984	12.578
1985	4.378
1986	23.722
1987	27.708
1988	28.9
1989	17.401
1990	9
1991	20.168
1992	24.476
1993	22.472
1994	34.862
1995	49.32
1996	23.918
1997	16.544
1998	18.454
1999	20.24
2000	12.292
2001	11.538
2002	15.827
2003	15.573
2004	15.324
2005	10.252
2006	12
2007	18.414
2008	25.304
2009	10.816
2010	12.299
2011	21.527
2012	30.57
2013	34.7
2014	15.56
2015	11.919
2016	9.05
2017	9.641
2018	31.165
2019	37.173
2020	31
2021	29
2022	27
2023	25.5
2024	25