Year	Percent change
1981	-28.96
1982	-30.085
1983	3.933
1984	6.591
1985	10.068
1986	31.207
1987	14.74
1988	-41.031
1989	27.537
1990	59.698
1991	9.975
1992	-8.101
1993	-5.785
1994	23.158
1995	-24.138
1996	-7.77
1997	-23.055
1998	-6.739
1999	-34.796
2000	123.353
2001	20.179
2002	37.519
2003	17.977
2004	-14.122
2005	1.241
2006	7.067
2007	-5.081
2008	-10.952
2009	17.416
2010	12.41
2011	25.931
2012	112.789
2013	52.795
2014	3.773
2015	-25.646
2016	21.365
2017	-12.048
2018	9.682
2019	23.072
2020	7.07
2021	6.428
2022	8.581
2023	8.267
2024	7.95