Year	Percent change (Units)
1980	-29.111
1981	20.637
1982	8.509
1983	15.881
1984	22.861
1985	3.039
1986	19.745
1987	-10.247
1988	-39.838
1989	172.249
1990	-11.326
1991	9.362
1992	19.327
1993	65.154
1994	46.429
1995	32.878
1996	20.415
1997	0.370
1998	0.236
1999	-7.238
2000	-6.540
2001	3.481
2002	19.690
2003	24.802
2004	27.502
2005	6.952
2006	16.827
2007	33.336
2008	16.488
2009	-5.559
2010	4.404
2011	2.222
2012	12.000
2013	20.448
2014	12.564
2015	15.604
2016	12.617
2017	17.536
2018	9.335
2019	4.171
2020	1.975
2021	17.480
2022	2.794
2023	-4.724
2024	8.740
2025	6.632
2026	8.247
2027	7.697
2028	7.525
2029	7.372