Year	Percent change (Units)
1992	0.562
1993	-6.751
1994	-1.360
1995	-3.481
1996	-3.732
1997	-1.216
1998	0.114
1999	2.919
2000	0.713
2001	1.793
2002	3.234
2003	3.186
2004	2.779
2005	3.111
2006	4.825
2007	5.017
2008	5.806
2009	1.616
2010	4.147
2011	7.293
2012	4.842
2013	5.001
2014	7.193
2015	7.309
2016	7.123
2017	5.458
2018	4.774
2019	5.545
2020	1.316
2021	4.522
2022	3.876
2023	6.989
2024	6.513
2025	6.008
2026	5.510
2027	5.500
2028	5.500
2029	5.500