Year	Percent change (Units)
1980	7.808
1981	4.936
1982	2.749
1983	1.881
1984	2.251
1985	2.038
1986	0.608
1987	0.128
1988	0.654
1989	2.294
1990	3.071
1991	3.273
1992	1.727
1993	1.254
1994	0.690
1995	-0.088
1996	0.138
1997	1.699
1998	0.652
1999	-0.346
2000	-0.687
2001	-0.694
2002	-0.897
2003	-0.263
2004	-0.010
2005	-0.288
2006	0.256
2007	0.047
2008	1.383
2009	-1.331
2010	-0.742
2011	-0.278
2012	-0.049
2013	0.332
2014	2.758
2015	0.799
2016	-0.124
2017	0.486
2018	0.989
2019	0.468
2020	-0.027
2021	-0.235
2022	2.497
2023	3.268
2024	2.237
2025	2.097
2026	2.006
2027	2.004
2028	2.004
2029	2.004