Year	Percent change (Units)
1980	2.926
1981	1.513
1982	5.577
1983	-3.072
1984	5.362
1985	9.009
1986	11.987
1987	-6.567
1988	-2.703
1989	2.151
1990	2.401
1991	0.388
1992	1.721
1993	4.960
1994	5.382
1995	5.587
1996	8.840
1997	12.619
1998	9.210
1999	-1.836
2000	2.806
2001	1.974
2002	0.540
2003	0.827
2004	9.148
2005	7.909
2006	8.827
2007	9.729
2008	4.479
2009	-10.240
2010	7.984
2011	3.935
2012	2.935
2013	5.043
2014	2.179
2015	1.883
2016	1.933
2017	1.841
2018	1.390
2019	5.336
2020	-9.855
2021	1.823
2022	12.520
2023	0.725
2024	1.650
2025	2.105
2026	2.297
2027	2.310
2028	2.269
2029	2.239