Year	Percent change (Units)
1980	-2.629
1981	5.198
1982	1.976
1983	-2.000
1984	0.400
1985	71.615
1986	12.407
1987	9.833
1988	12.046
1989	14.006
1990	17.875
1991	59.747
1992	2.310
1993	8.242
1994	-13.535
1995	58.119
1996	-10.459
1997	38.718
1998	-30.730
1999	2.836
2000	37.519
2001	-2.272
2002	14.595
2003	39.962
2004	-8.369
2005	3.428
2006	16.897
2007	44.970
2008	5.569
2009	-4.104
2010	6.156
2011	-14.164
2012	17.017
2013	27.989
2014	13.614
2015	-8.014
2016	21.863
2017	3.824
2018	4.246
2019	-11.929
2020	5.432
2021	-4.449
2022	-12.476
2023	18.804
2024	14.236
2025	9.916
2026	9.077
2027	9.047
2028	7.884
2029	8.006