Year	Percent change (Units)
1981	7.422
1982	1.369
1983	1.013
1984	0.668
1985	0.172
1986	0.497
1987	2.764
1988	2.838
1989	2.706
1990	5.628
1991	0.888
1992	1.100
1993	-0.062
1994	2.179
1995	2.594
1996	3.900
1997	0.369
1998	-0.184
1999	1.558
2000	3.530
2001	-1.959
2002	2.308
2003	0.541
2004	4.940
2005	5.880
2006	4.519
2007	4.248
2008	1.360
2009	3.905
2010	0.527
2011	3.266
2012	1.152
2013	0.811
2014	0.070
2015	-0.159
2016	0.453
2017	1.161
2018	0.569
2019	0.529
2020	-0.082
2021	4.157
2022	6.075
2023	1.549
2024	2.245
2025	2.276
2026	2.422
2027	2.666
2028	2.359
2029	2.308