Year	Percent change (Units)
1980	-2.487
1981	-1.787
1982	-0.458
1983	3.694
1984	3.351
1985	5.163
1986	-13.634
1987	-9.653
1988	-1.245
1989	6.649
1990	6.242
1991	1.143
1992	3.967
1993	1.679
1994	-7.807
1995	6.892
1996	6.736
1997	9.089
1998	2.074
1999	4.940
2000	4.952
2001	-2.225
2002	3.640
2003	7.286
2004	3.386
2005	5.276
2006	-2.356
2007	-1.933
2008	-3.264
2009	-10.312
2010	-2.883
2011	-3.815
2012	-4.004
2013	-6.890
2014	0.474
2015	1.755
2016	7.883
2017	2.628
2018	-6.888
2019	-4.463
2020	-9.322
2021	23.775
2022	32.281
2023	9.262
2024	2.194
2025	1.200
2026	0.700
2027	0.200
2028	0.200
2029	0.200