Year	Percent change (Units)
1991	120.200
1992	202.875
1993	268.414
1994	193.414
1995	0.218
1996	46.831
1997	30.032
1998	9.590
1999	7.487
2000	11.363
2001	6.255
2002	1.067
2003	5.060
2004	8.247
2005	12.708
2006	4.345
2007	9.643
2008	27.974
2009	7.594
2010	8.231
2011	8.792
2012	13.886
2013	10.568
2014	12.949
2015	6.783
2016	0.771
2017	4.278
2018	6.808
2019	7.320
2020	3.735
2021	7.359
2022	15.153
2023	10.348
2024	9.747
2025	9.950
2026	8.850
2027	7.800
2028	7.100
2029	6.800