Year	Percent change (Units)
1983	-23.482
1984	-4.853
1985	19.307
1986	29.320
1987	-7.599
1988	5.645
1989	-7.110
1990	17.352
1991	2.976
1992	-13.080
1993	-28.633
1994	-6.020
1995	24.874
1996	10.619
1997	-3.678
1998	8.992
1999	-11.420
2000	-8.383
2001	10.237
2002	11.633
2003	24.684
2004	4.045
2005	-2.189
2006	-1.776
2007	6.408
2008	5.894
2009	8.820
2010	-0.432
2011	23.581
2012	-7.580
2013	17.641
2014	2.981
2015	7.250
2016	-1.462
2017	5.070
2018	4.989
2019	1.767
2020	8.426
2021	6.131
2022	9.086
2023	5.665
2024	5.499
2025	4.901
2026	7.061
2027	7.045
2028	7.108
2029	4.813
