Year	Percent change (Units)
1980	8.810
1981	9.611
1982	-3.934
1983	5.318
1984	14.695
1985	-2.056
1986	-6.979
1987	1.566
1988	5.529
1989	-2.907
1990	-7.900
1991	3.600
1992	17.500
1993	23.500
1994	22.900
1995	15.100
1996	-7.046
1997	12.300
1998	5.900
1999	10.200
2000	24.735
2001	3.781
2002	24.203
2003	14.938
2004	14.938
2005	13.509
2006	9.948
2007	40.368
2008	16.064
2009	-2.158
2010	24.937
2011	13.424
2012	0.878
2013	15.818
2014	8.520
2015	5.257
2016	17.735
2017	8.474
2018	4.468
2019	1.735
2020	-7.665
2021	11.531
2022	4.774
2023	-0.187
2024	4.065
2025	6.667
2026	6.382
2027	5.425
2028	5.256
2029	5.347