Year	Percent change (Units)
1991	222.803
1992	199.213
1993	295.481
1994	61.739
1995	27.750
1996	56.900
1997	151.420
1998	40.570
1999	54.810
2000	40.710
2001	30.193
2002	17.890
2003	14.241
2004	9.158
2005	8.717
2006	4.879
2007	6.561
2008	6.300
2009	4.751
2010	7.978
2011	3.133
2012	4.964
2013	1.569
2014	0.828
2015	-0.947
2016	-0.534
2017	3.320
2018	3.261
2019	4.047
2020	2.068
2021	8.188
2022	16.371
2023	6.606
2024	4.681
2025	3.462
2026	2.999
2027	3.035
2028	2.964
2029	3.091