Year	Percent change (Units)
1980	42.530
1981	10.151
1982	4.957
1983	4.332
1984	7.493
1985	-5.103
1986	9.307
1987	14.026
1988	27.738
1989	8.997
1990	14.031
1991	7.637
1992	8.332
1993	18.435
1994	16.114
1995	19.489
1996	10.310
1997	11.286
1998	-10.079
1999	6.500
2000	21.300
2001	-10.725
2002	4.695
2003	7.634
2004	23.131
2005	13.031
2006	10.148
2007	6.508
2008	11.462
2009	-13.640
2010	18.211
2011	6.269
2012	-0.270
2013	3.350
2014	-1.685
2015	-1.646
2016	-1.568
2017	7.108
2018	4.661
2019	-1.388
2020	-1.903
2021	9.954
2022	3.279
2023	-6.242
2024	11.772
2025	5.048
2026	3.955
2027	4.404
2028	3.185
2029	2.894