Year	Percent change (Units)
1980	-15.913
1981	-32.025
1982	0.614
1983	-1.729
1984	-7.703
1985	-3.383
1986	16.730
1987	-26.272
1988	20.770
1989	20.199
1990	19.981
1991	-19.156
1992	-6.950
1993	-6.959
1994	-6.433
1995	-2.483
1996	-16.207
1997	3.652
1998	-7.377
1999	2.709
2000	3.027
2001	-5.208
2002	-17.803
2003	16.250
2004	59.608
2005	9.104
2006	9.179
2007	3.440
2008	-6.528
2009	-7.437
2010	-0.677
2011	-68.933
2012	217.170
2013	-23.911
2014	-54.822
2015	4.627
2016	3.947
2017	133.212
2018	43.281
2019	-10.009
2020	-69.433
2021	237.976
2022	16.005
2023	-16.406
2024	0.649
2025	1.699
2026	-0.854
2027	-3.788
2028	-3.000
2029	-2.916