Year	Percent change (Units)
1980	-5.277
1981	72.252
1982	-5.335
1983	-18.668
1984	-1.727
1985	-21.440
1986	-10.682
1987	161.202
1988	-19.771
1989	0.333
1990	21.025
1991	-12.509
1992	43.047
1993	-22.607
1994	-16.991
1995	30.633
1996	-8.720
1997	3.930
1998	-8.501
1999	17.505
2000	3.874
2001	1.020
2002	13.941
2003	-16.681
2004	-1.629
2005	23.468
2006	-12.832
2007	5.061
2008	-3.559
2009	-9.025
2010	6.334
2011	23.341
2012	18.004
2013	4.316
2014	-5.259
2015	-7.063
2016	5.048
2017	5.002
2018	-14.864
2019	9.450
2020	-2.891
2021	22.744
2022	25.051
2023	-0.699
2024	5.745
2025	1.348
2026	3.125
2027	1.776
2028	1.515
2029	1.297