Year	Percent change (Units)
1980	-27.936
1981	13.517
1982	6.027
1983	-17.913
1984	-13.720
1985	-6.003
1986	30.585
1987	39.484
1988	65.971
1989	8.785
1990	-14.802
1991	-1.504
1992	-34.156
1993	-0.346
1994	-20.159
1995	10.410
1996	24.495
1997	-8.031
1998	0.756
1999	-13.453
2000	4.727
2001	-15.948
2002	-0.922
2003	4.777
2004	35.098
2005	28.235
2006	39.352
2007	76.208
2008	13.099
2009	-22.238
2010	3.102
2011	12.359
2012	-15.340
2013	-12.256
2014	-11.924
2015	-4.053
2016	-15.788
2017	0.920
2018	6.281
2019	7.749
2020	6.711
2021	-0.480
2022	6.553
2023	-14.735
2024	41.138
2025	20.519
2026	-11.054
2027	-7.688
2028	4.960
2029	13.429