Year	Percent change (Units)
1980	-12.750
1981	22.024
1982	-19.627
1983	6.785
1984	12.207
1985	-0.482
1986	2.236
1987	1.483
1988	13.654
1989	3.110
1990	-7.866
1991	0.286
1992	7.126
1993	50.618
1994	10.133
1995	6.652
1996	6.563
1997	21.513
1998	6.587
1999	14.947
2000	14.421
2001	-4.548
2002	-0.638
2003	8.179
2004	-0.544
2005	3.079
2006	3.254
2007	3.353
2008	-14.013
2009	-12.727
2010	36.313
2011	4.101
2012	7.276
2013	9.977
2014	12.002
2015	9.282
2016	7.703
2017	3.340
2018	4.267
2019	-0.952
2020	-31.625
2021	26.017
2022	15.498
2023	-1.628
2024	5.267
2025	5.265
2026	4.711
2027	5.480
2028	7.248
2029	6.587