Year	Percent change (Units)
1980	6.443
1981	8.376
1982	8.331
1983	5.792
1984	5.914
1985	5.679
1986	9.426
1987	3.542
1988	5.146
1989	4.183
1990	-2.486
1991	-9.199
1992	-9.256
1993	-3.169
1994	2.134
1995	6.376
1996	2.235
1997	3.897
1998	3.340
1999	3.070
2000	1.146
2001	4.639
2002	5.267
2003	7.357
2004	9.425
2005	6.507
2006	8.163
2007	8.757
2008	7.819
2009	-2.069
2010	7.313
2011	17.291
2012	12.320
2013	11.649
2014	7.885
2015	2.410
2016	1.490
2017	5.637
2018	7.745
2019	5.602
2020	-4.558
2021	1.637
2022	5.033
2023	7.023
2024	6.536
2025	5.960
2026	5.480
2027	5.374
2028	5.170
2029	5.171