Year	Percent change (Units)
1991	104.047
1992	236.580
1993	30.941
1994	15.818
1995	6.015
1996	17.402
1997	42.073
1998	8.686
1999	-1.029
2000	4.205
2001	3.527
2002	1.681
2003	3.298
2004	2.204
2005	2.038
2006	2.513
2007	3.027
2008	2.215
2009	3.501
2010	3.495
2011	1.743
2012	2.463
2013	1.776
2014	0.719
2015	1.937
2016	2.165
2017	1.808
2018	1.799
2019	1.150
2020	1.051
2021	3.700
2022	7.425
2023	3.950
2024	3.003
2025	3.003
2026	3.003
2027	3.003
2028	3.003
2029	3.003