Year	Percent change (Units)
1991	59.884
1992	-12.633
1993	11.993
1994	0.269
1995	23.866
1996	-17.069
1997	34.386
1998	11.336
1999	-18.510
2000	-17.469
2001	41.528
2002	-0.581
2003	26.991
2004	-18.522
2005	27.775
2006	-2.843
2007	19.409
2008	11.587
2009	-1.209
2010	21.543
2011	4.679
2012	-11.032
2013	-2.859
2014	18.104
2015	5.404
2016	-29.002
2017	1.473
2018	27.061
2019	45.383
2020	-19.005
2021	-25.357
2022	-4.882
2023	4.146
2024	-0.108
2025	-3.625
2026	-1.957
2027	0.204
2028	-0.424
2029	0.723