Year	Percent change (Units)
1980	-13.199
1981	28.437
1982	-10.689
1983	6.322
1984	19.811
1985	3.773
1986	-30.797
1987	21.713
1988	75.479
1989	-0.171
1990	-66.872
1991	-24.522
1992	40.065
1993	25.741
1994	-3.200
1995	21.000
1996	-11.400
1997	-0.700
1998	11.700
1999	6.800
2000	10.644
2001	12.562
2002	6.291
2003	15.151
2004	26.243
2005	14.348
2006	15.915
2007	22.616
2008	4.864
2009	-21.508
2010	-0.302
2011	9.616
2012	5.379
2013	4.336
2014	5.145
2015	4.734
2016	5.110
2017	7.403
2018	5.761
2019	5.224
2020	-4.933
2021	9.128
2022	13.301
2023	2.024
2024	4.398
2025	6.473
2026	2.602
2027	3.032
2028	3.099
2029	2.856