Year	Percent change (Units)
1980	16.983
1981	13.320
1982	1.432
1983	4.972
1984	15.320
1985	5.254
1986	-5.120
1987	-0.103
1988	6.696
1989	9.474
1990	7.183
1991	5.237
1992	4.380
1993	0.363
1994	2.167
1995	4.186
1996	4.833
1997	11.085
1998	-2.424
1999	2.001
2000	13.023
2001	-6.633
2002	7.892
2003	9.629
2004	14.371
2005	7.120
2006	10.306
2007	8.703
2008	1.588
2009	-23.383
2010	24.861
2011	-0.120
2012	0.146
2013	0.810
2014	9.342
2015	3.211
2016	1.618
2017	6.619
2018	3.760
2019	-1.458
2020	-11.595
2021	11.872
2022	5.283
2023	3.021
2024	3.281
2025	1.715
2026	2.456
2027	1.755
2028	1.577
2029	1.467