Year	Percent change (Units)
1980	-6.527
1981	20.786
1982	1.078
1983	14.420
1984	5.331
1985	18.485
1986	14.813
1987	3.779
1988	12.306
1989	2.088
1990	7.700
1991	-3.300
1992	16.110
1993	4.591
1994	4.858
1995	0.753
1996	9.418
1997	13.673
1998	-4.873
1999	6.571
2000	12.779
2001	9.732
2002	0.985
2003	-7.410
2004	-6.742
2005	7.564
2006	1.900
2007	4.425
2008	18.312
2009	0.162
2010	4.598
2011	4.586
2012	12.199
2013	9.930
2014	2.518
2015	3.268
2016	-10.711
2017	2.705
2018	5.765
2019	-0.911
2020	1.981
2021	-12.601
2022	17.762
2023	5.799
2024	8.006
2025	3.893
2026	4.546
2027	3.601
2028	3.359
2029	3.572