Year	Percent change (Units)
1980	13.994
1981	12.276
1982	6.864
1983	5.452
1984	5.099
1985	2.358
1986	-0.461
1987	6.283
1988	4.418
1989	6.555
1990	3.412
1991	8.112
1992	3.302
1993	-0.969
1994	0.800
1995	2.838
1996	1.808
1997	3.551
1998	1.715
1999	2.928
2000	1.121
2001	3.458
2002	-1.049
2003	1.929
2004	1.707
2005	7.019
2006	7.609
2007	3.053
2008	10.864
2009	2.227
2010	4.285
2011	10.585
2012	2.395
2013	2.827
2014	2.481
2015	-1.500
2016	2.502
2017	3.699
2018	2.042
2019	2.427
2020	0.395
2021	2.163
2022	5.679
2023	4.827
2024	2.714
2025	2.574
2026	2.427
2027	2.427
2028	2.427
2029	2.427