Year	Percent change (Units)
1980	1.443
1981	-4.953
1982	-26.020
1983	-6.910
1984	6.669
1985	6.395
1986	-9.550
1987	-2.479
1988	-6.817
1989	-1.335
1990	-8.753
1991	36.027
1992	30.507
1993	8.351
1994	11.959
1995	6.992
1996	15.934
1997	-0.472
1998	0.711
1999	-0.334
2000	-3.251
2001	0.157
2002	0.176
2003	1.447
2004	-0.364
2005	0.918
2006	-1.566
2007	1.161
2008	-1.230
2009	0.355
2010	-0.234
2011	0.452
2012	-0.193
2013	-0.535
2014	0.087
2015	0.396
2016	-0.577
2017	-0.240
2018	0.352
2019	3.502
2020	186.382
2021	47.088
2022	105.630
2023	38.233
2024	43.036
2025	4.127
2026	21.265
2027	23.982
2028	14.637
2029	12.771