Year	Percent change (Units)
1980	7.300
1981	5.533
1982	1.885
1983	-4.967
1984	-10.585
1985	-5.624
1986	29.500
1987	0.457
1988	0.842
1989	-6.520
1990	-17.100
1991	-27.800
1992	-8.100
1993	-0.900
1994	-16.276
1995	11.770
1996	24.662
1997	13.325
1998	29.870
1999	-22.744
2000	20.050
2001	5.487
2002	54.107
2003	-1.975
2004	30.534
2005	63.663
2006	14.521
2007	-1.708
2008	-6.528
2009	11.096
2010	5.406
2011	-15.952
2012	4.437
2013	6.684
2014	-5.350
2015	24.971
2016	-10.903
2017	7.615
2018	-18.645
2019	16.362
2020	2.639
2021	-8.064
2022	13.377
2023	-65.191
2024	46.865
2025	51.531
2026	8.011
2027	-3.708
2028	1.926
2029	-0.945