Year	Percent change (Units)
1980	5.847
1981	5.345
1982	5.233
1983	3.314
1984	6.725
1985	4.957
1986	4.281
1987	1.454
1988	2.698
1989	2.250
1990	6.174
1991	10.821
1992	-3.135
1993	7.477
1994	8.036
1995	6.051
1996	12.162
1997	10.291
1998	-1.646
1999	2.879
2000	8.418
2001	-1.948
2002	3.727
2003	5.940
2004	5.445
2005	6.242
2006	7.668
2007	6.797
2008	5.950
2009	3.539
2010	8.016
2011	8.669
2012	8.632
2013	4.052
2014	6.378
2015	4.206
2016	5.054
2017	6.461
2018	2.310
2019	-0.220
2020	-4.625
2021	3.512
2022	-7.824