Year	Percent change (Units)
1980	-8.986
1981	-13.295
1982	-16.259
1983	-8.766
1984	25.781
1985	-20.551
1986	18.987
1987	-11.662
1988	13.336
1989	2.330
1990	12.195
1991	-17.866
1992	11.942
1993	-10.985
1994	-6.449
1995	0.174
1996	27.812
1997	28.710
1998	28.693
1999	63.055
2000	4.993
2001	-6.822
2002	5.037
2003	-9.784
2004	25.402
2005	6.596
2006	15.153
2007	17.060
2008	16.799
2009	4.407
2010	30.683
2011	15.468
2012	10.237
2013	1.610
2014	-0.108
2015	-4.369
2016	-4.924
2017	-1.276
2018	5.456
2019	-0.554
2020	-1.354
2021	-0.635
2022	1.506
2023	2.586
2024	-2.616
2025	4.595
2026	11.524
2027	15.556
2028	4.922
2029	0.496