Year	Percent change (Units)
1980	-3.159
1981	3.811
1982	8.088
1983	-7.398
1984	20.960
1985	-0.161
1986	-1.199
1987	10.758
1988	-3.632
1989	20.786
1990	6.973
1991	-7.531
1992	10.117
1993	7.965
1994	14.997
1995	8.564
1996	7.986
1997	3.567
1998	-0.503
1999	15.731
2000	-1.172
2001	3.175
2002	11.250
2003	8.356
2004	17.391
2005	5.519
2006	-2.054
2007	8.680
2008	3.312
2009	-15.990
2010	11.468
2011	6.773
2012	3.870
2013	6.662
2014	8.937
2015	5.446
2016	3.596
2017	7.377
2018	6.484
2019	0.930
2020	-11.249
2021	21.011
2022	0.118
2023	-4.800
2024	-1.051
2025	2.885
2026	3.528
2027	3.617
2028	3.995
2029	3.777