Year	Percent change (Units)
1989	18.100
1990	33.400
1991	32.200
1992	21.600
1993	21.100
1994	21.200
1995	28.300
1996	19.756
1997	18.425
1998	10.312
1999	11.186
2000	10.081
2001	6.818
2002	4.817
2003	5.731
2004	5.451
2005	3.332
2006	6.523
2007	7.380
2008	3.500
2009	5.558
2010	4.674
2011	4.073
2012	4.978
2013	0.413
2014	-0.931
2015	0.873
2016	1.767
2017	2.139
2018	2.738
2019	3.995
2020	2.740
2021	7.363
2022	24.549
2023	5.500
2024	4.355
2025	2.871
2026	2.975
2027	3.000
2028	3.000
2029	3.000