Year	Percent change (Units)
1991	6.293
1992	8.208
1993	4.002
1994	6.722
1995	5.669
1996	4.635
1997	5.231
1998	6.007
1999	3.776
2000	6.182
2001	3.804
2002	3.935
2003	3.747
2004	3.973
2005	5.592
2006	3.170
2007	3.338
2008	3.648
2009	3.866
2010	7.702
2011	-12.715
2012	2.393
2013	4.824
2014	-0.189
2015	-27.995
2016	-9.375
2017	-5.072
2018	0.752
2019	2.100
2020	-8.500
2021	-1.000
2022	1.500
2023	-2.000
2024	-1.000
2025	1.500
2026	7.000
2027	6.500
2028	6.000
2029	5.500