Year	Percent change (Units)
1980	10.784
1981	11.563
1982	1.253
1983	-1.029
1984	0.093
1985	1.977
1986	-23.611
1987	-23.997
1988	-1.420
1989	23.733
1990	97.622
1991	-20.471
1992	6.950
1993	-3.798
1994	12.844
1995	5.845
1996	-12.233
1997	-6.259
1998	9.047
1999	6.774
2000	4.109
2001	4.368
2002	27.784
2003	7.060
2004	25.507
2005	6.701
2006	1.089
2007	21.025
2008	33.910
2009	2.596
2010	-0.157
2011	7.014
2012	11.404
2013	9.578
2014	11.371
2015	-5.562
2016	-1.864
2017	-1.974
2018	-2.950
2019	-7.756
2020	-18.154
2021	-4.079
2022	-6.360
2023	3.000
2024	9.697
2025	7.174
2026	4.786
2027	2.051
2028	1.390
2029	0.871