Year	Percent change (Units)
1980	-0.257
1981	2.537
1982	-1.803
1983	4.584
1984	7.236
1985	4.169
1986	3.463
1987	3.455
1988	4.177
1989	3.672
1990	1.886
1991	-0.109
1992	3.522
1993	2.752
1994	4.029
1995	2.685
1996	3.773
1997	4.447
1998	4.483
1999	4.788
2000	4.078
2001	0.956
2002	1.700
2003	2.796
2004	3.848
2005	3.483
2006	2.785
2007	2.004
2008	0.114
2009	-2.576
2010	2.695
2011	1.564
2012	2.289
2013	2.118
2014	2.524
2015	2.946
2016	1.820
2017	2.458
2018	2.967
2019	2.467
2020	-2.214
2021	5.800
2022	1.936
2023	2.531
2024	2.725
2025	1.881
2026	2.028
2027	2.120
2028	2.122
2029	2.122