Year	Percent change (Units)
1980	-10.060
1981	5.882
1982	5.497
1983	0.384
1984	4.775
1985	6.876
1986	9.742
1987	10.163
1988	6.791
1989	4.465
1990	7.187
1991	4.435
1992	6.513
1993	5.082
1994	4.136
1995	4.288
1996	5.588
1997	5.687
1998	6.072
1999	2.611
2000	8.192
2001	3.214
2002	1.627
2003	5.984
2004	4.299
2005	1.453
2006	4.514
2007	5.727
2008	5.387
2009	3.315
2010	4.377
2011	4.078
2012	3.496
2013	3.360
2014	3.827
2015	3.691
2016	3.862
2017	3.938
2018	4.007
2019	2.891
2020	-14.547
2021	3.404
2022	8.881
2023	6.870
2024	4.861
2025	3.676
2026	3.463
2027	3.329
2028	3.329
2029	3.329