Year	Percent change (Units)
1980	-0.300
1981	1.679
1982	3.023
1983	2.362
1984	7.516
1985	0.300
1986	2.382
1987	3.900
1988	9.739
1989	7.832
1990	4.744
1991	2.288
1992	4.262
1993	11.500
1994	8.300
1995	8.900
1996	3.717
1997	9.994
1998	4.759
1999	4.486
2000	11.807
2001	2.134
2002	7.974
2003	-0.302
2004	6.892
2005	4.367
2006	4.408
2007	4.706
2008	-2.243
2009	-10.694
2010	8.248
2011	4.349
2012	-1.624
2013	2.709
2014	1.813
2015	1.291
2016	3.116
2017	0.856
2018	0.737
2019	0.048
2020	-6.399
2021	14.718
2022	7.196
2023	-3.324
2024	-0.556
2025	2.920
2026	3.411
2027	3.318
2028	3.298
2029	3.193