Year	Percent change (Units)
1980	5.334
1981	7.236
1982	3.731
1983	-0.487
1984	9.153
1985	7.636
1986	-0.817
1987	1.114
1988	6.428
1989	10.375
1990	7.523
1991	16.364
1992	-1.069
1993	-6.570
1994	9.476
1995	6.974
1996	6.038
1997	11.780
1998	7.078
1999	5.504
2000	14.395
2001	6.520
2002	3.089
2003	2.253
2004	9.659
2005	7.417
2006	12.851
2007	9.823
2008	0.652
2009	-16.726
2010	15.898
2011	9.092
2012	3.215
2013	0.575
2014	4.059
2015	3.920
2016	1.924
2017	5.835
2018	1.960
2019	1.092
2020	-9.404
2021	9.624
2022	2.116
2023	-2.408
2024	2.440
2025	3.651
2026	2.979
2027	3.072
2028	2.925
2029	2.775