Year	Percent change (Units)
1980	9.400
1981	-5.500
1982	-3.500
1983	-3.400
1984	10.121
1985	25.809
1986	21.298
1987	1.177
1988	19.268
1989	-8.236
1990	-4.936
1991	21.074
1992	6.241
1993	11.795
1994	5.982
1995	4.487
1996	11.357
1997	1.205
1998	36.295
1999	8.552
2000	-7.040
2001	10.120
2002	-3.530
2003	14.297
2004	22.305
2005	17.312
2006	26.795
2007	24.539
2008	25.990
2009	-15.568
2010	30.331
2011	47.187
2012	11.283
2013	1.867
2014	-14.686
2015	0.423
2016	-2.902
2017	8.030
2018	8.122
2019	10.527
2020	-7.325
2021	13.477
2022	8.861
2023	-3.665
2024	5.628
2025	6.334
2026	5.962
2027	5.314
2028	5.442
2029	6.819