Year	Percent change (Units)
1980	-3.622
1981	-25.718
1982	-25.710
1983	19.029
1984	12.304
1985	7.560
1986	6.728
1987	12.837
1988	10.009
1989	20.400
1990	11.189
1991	-3.876
1992	22.348
1993	15.747
1994	5.568
1995	2.501
1996	0.954
1997	19.430
1998	27.905
1999	-0.312
2000	-4.187
2001	5.135
2002	18.631
2003	20.121
2004	18.800
2005	26.993
2006	23.637
2007	18.339
2008	25.329
2009	-20.367
2010	9.874
2011	16.307
2012	6.704
2013	0.467
2014	10.220
2015	-5.557
2016	5.541
2017	10.750
2018	6.468
2019	-2.723
2020	-12.929
2021	19.246
2022	6.022
2023	5.612
2024	8.599
2025	7.345
2026	6.696
2027	6.418
2028	6.275
2029	6.239