Year	Percent change (Units)
1980	3.030
1981	-2.941
1982	3.030
1983	2.941
1984	-1.714
1985	-1.744
1986	2.959
1987	4.023
1988	-4.972
1989	-7.558
1990	-15.723
1991	4.478
1992	2.143
1993	0.914
1994	0.984
1995	1.359
1996	0.969
1997	1.077
1998	1.197
1999	1.369
2000	-5.980
2001	5.211
2002	8.060
2003	-26.017
2004	23.261
2005	-7.671
2006	4.610
2007	5.747
2008	-19.224
2009	14.463
2010	3.687
2011	-18.991
2012	43.662
2013	41.138
2014	8.354
2015	15.083
2016	0.460
2017	10.253
2018	2.335
2019	-1.821
2020	4.609
2021	7.753
2022	4.297
2023	7.735
2024	6.961
2025	5.779
2026	5.891
2027	5.742
2028	5.001
2029	2.900