Year	Percent change
1980	-43.145
1981	-22.534
1982	5.512
1983	46.461
1984	21.977
1985	13.196
1986	29.093
1987	18.607
1988	2.457
1989	-28.041
1990	32.598
1991	32.633
1992	51.364
1993	22.835
1994	26.915
1995	13.473
1996	36.174
1997	24.432
1998	-4.046
1999	14.787
2000	-1.856
2001	6.277
2002	10.509
2003	10.356
2004	17.4
2005	7.575
2006	14.366
2007	13.7
2008	3.216
2009	4.808
2010	6.356
2011	5.596
2012	16.202
2013	17.249
2014	11.813
2015	10.136
2016	10.73
2017	17.279
2018	12.975
2019	12.891
2020	12.547
2021	12.454
2022	12.462
2023	12.328
2024	12.382