Year	Percent change (Units)
1991	14.040
1992	33.025
1993	139.138
1994	255.846
1995	-49.322
1996	4.169
1997	16.996
1998	14.867
1999	71.896
2000	44.678
2001	0.878
2002	28.390
2003	13.055
2004	9.065
2005	20.075
2006	4.752
2007	8.333
2008	9.376
2009	1.300
2010	10.300
2011	15.200
2012	4.300
2013	0.600
2014	3.900
2015	25.100
2016	52.400
2017	9.296
2018	5.441
2019	4.215
2020	60.739
2021	60.694
2022	54.580
2023	32.617
2024	14.226
2025	11.018
2026	8.035
2027	6.568
2028	5.000
2029	5.000