Year	Percent change (Units)
1981	9.470
1982	3.244
1983	0.338
1984	1.734
1985	0.212
1986	-0.236
1987	2.078
1988	2.577
1989	2.832
1990	4.368
1991	2.238
1992	1.486
1993	0.967
1994	1.438
1995	1.915
1996	3.312
1997	1.886
1998	0.059
1999	0.671
2000	3.077
2001	0.583
2002	0.190
2003	1.388
2004	2.536
2005	5.611
2006	5.184
2007	4.228
2008	5.210
2009	0.278
2010	2.474
2011	2.899
2012	1.346
2013	1.061
2014	0.566
2015	-0.751
2016	-0.294
2017	1.752
2018	1.272
2019	0.084
2020	-0.497
2021	2.410
2022	6.018
2023	2.804
2024	1.900
2025	2.261
2026	2.350
2027	2.545
2028	2.510
2029	2.333