Year	Percent change (Units)
1980	5.862
1981	21.152
1982	22.730
1983	25.106
1984	29.300
1985	19.335
1986	11.666
1987	9.402
1988	9.580
1989	12.611
1990	13.370
1991	11.428
1992	8.863
1993	5.930
1994	4.971
1995	3.969
1996	2.936
1997	1.890
1998	2.215
1999	2.170
2000	2.805
2001	4.410
2002	3.701
2003	3.237
2004	2.510
2005	2.130
2006	3.046
2007	2.422
2008	2.652
2009	-0.903
2010	1.391
2011	3.554
2012	2.776
2013	0.440
2014	-0.160
2015	0.508
2016	0.636
2017	1.556
2018	1.168
2019	0.300
2020	-0.121
2021	0.941
2022	8.103
2023	5.264
2024	2.248
2025	2.005
2026	2.031
2027	2.042
2028	2.044
2029	2.045