Year	Percent change (Units)
1980	4.035
1981	2.661
1982	1.400
1983	-1.200
1984	1.600
1985	11.300
1986	7.955
1987	-0.236
1988	5.796
1989	2.150
1990	-0.603
1991	9.070
1992	0.233
1993	3.461
1994	1.315
1995	5.716
1996	11.015
1997	6.317
1998	7.308
1999	7.333
2000	1.888
2001	6.613
2002	4.353
2003	7.802
2004	4.478
2005	8.662
2006	6.253
2007	4.111
2008	5.800
2009	2.962
2010	8.446
2011	6.623
2012	6.453
2013	5.793
2014	4.327
2015	3.921
2016	5.958
2017	6.203
2018	6.605
2019	5.486
2020	1.922
2021	6.938
2022	1.780
2023	3.561
2024	5.464
2025	5.793
2026	4.975
2027	4.918
2028	4.947
2029	4.976