Year	Percent change (Units)
1988	31.000
1989	89.000
1990	151.000
1991	150.000
1992	112.000
1993	41.000
1994	29.902
1995	-1.859
1996	10.034
1997	16.690
1998	7.982
1999	0.181
2000	0.341
2001	-0.527
2002	1.427
2003	-0.042
2004	5.265
2005	8.411
2006	4.201
2007	13.952
2008	12.520
2009	5.325
2010	3.143
2011	4.908
2012	2.541
2013	4.675
2014	1.040
2015	2.848
2016	3.875
2017	2.231
2018	1.632
2019	3.072
2020	2.876
2021	3.702
2022	2.876
2023	2.704
2024	2.937
2025	3.040
2026	3.040
2027	3.000
2028	3.000
2029	3.000