Year	Percent change (Units)
1980	8.487
1981	29.011
1982	19.315
1983	11.176
1984	28.085
1985	7.667
1986	6.614
1987	34.562
1988	36.295
1989	104.300
1990	75.300
1991	79.000
1992	12.500
1993	6.800
1994	16.095
1995	8.106
1996	4.485
1997	4.153
1998	4.770
1999	8.622
2000	5.864
2001	1.502
2002	6.089
2003	5.014
2004	5.457
2005	8.279
2006	4.163
2007	14.033
2008	6.370
2009	3.650
2010	4.430
2011	3.304
2012	3.476
2013	0.887
2014	1.172
2015	-1.814
2016	1.454
2017	1.510
2018	1.637
2019	2.061
2020	0.948
2021	5.672
2022	7.240
2023	2.016
2024	3.556
2025	5.534
2026	5.476
2027	5.494
2028	5.536
2029	5.641