Year	Percent change (Units)
1980	1.272
1981	0.110
1982	-0.788
1983	1.555
1984	2.826
1985	2.192
1986	2.417
1987	1.469
1988	3.736
1989	3.913
1990	5.723
1991	5.011
1992	1.920
1993	-0.977
1994	2.399
1995	1.541
1996	0.816
1997	1.785
1998	2.020
1999	1.887
2000	2.904
2001	1.687
2002	-0.201
2003	-0.703
2004	1.184
2005	0.726
2006	3.814
2007	2.982
2008	0.959
2009	-5.696
2010	4.185
2011	3.914
2012	0.427
2013	0.432
2014	2.217
2015	1.487
2016	2.230
2017	2.680
2018	0.984
2019	1.071
2020	-3.829
2021	3.169
2022	1.804
2023	-0.305
2024	0.150
2025	1.326
2026	1.451
2027	1.115
2028	0.830
2029	0.656