Year	Percent change (Units)
1980	-7.761
1981	2.136
1982	-0.674
1983	-3.443
1984	10.537
1985	-2.691
1986	3.756
1987	9.018
1988	18.661
1989	17.994
1990	8.106
1991	-1.112
1992	-1.087
1993	-1.285
1994	23.642
1995	11.420
1996	11.768
1997	0.512
1998	-6.804
1999	3.702
2000	9.562
2001	1.163
2002	0.787
2003	3.394
2004	8.504
2005	5.946
2006	4.704
2007	2.271
2008	0.733
2009	-15.560
2010	11.285
2011	5.728
2012	5.453
2013	3.169
2014	8.125
2015	0.440
2016	-1.175
2017	3.307
2018	3.814
2019	0.988
2020	-6.751
2021	5.142
2022	7.871
2023	-1.335
2024	2.188
2025	2.038
2026	1.703
2027	1.644
2028	1.425
2029	1.325