Year	Percent change (Units)
1980	8.039
1981	7.100
1982	4.810
1983	9.023
1984	10.049
1985	4.807
1986	11.512
1987	12.751
1988	8.024
1989	8.722
1990	5.541
1991	8.372
1992	8.310
1993	6.814
1994	7.503
1995	6.499
1996	6.177
1997	6.051
1998	4.205
1999	6.732
2000	6.314
2001	-1.402
2002	5.481
2003	4.225
2004	6.952
2005	5.383
2006	5.771
2007	6.851
2008	0.799
2009	-1.613
2010	10.245
2011	3.674
2012	2.222
2013	2.484
2014	4.719
2015	1.466
2016	2.165
2017	3.311
2018	2.787
2019	3.064
2020	3.387
2021	6.620
2022	2.588
2023	1.396
2024	3.072
2025	2.730
2026	2.516
2027	2.413
2028	2.327
2029	2.036