Year	Percent change (Units)
1991	5.343
1992	9.270
1993	-1.620
1994	3.005
1995	4.115
1996	3.196
1997	4.216
1998	3.291
1999	3.366
2000	3.497
2001	2.393
2002	6.680
2003	3.477
2004	6.632
2005	4.670
2006	3.948
2007	3.646
2008	2.650
2009	0.296
2010	6.039
2011	5.091
2012	5.062
2013	5.615
2014	6.093
2015	4.264
2016	0.034
2017	-1.027
2018	1.060
2019	-0.839
2020	-8.101
2021	3.525
2022	4.560
2023	3.154
2024	2.650
2025	2.643
2026	2.580
2027	2.596
2028	2.651
2029	2.635