Year	Percent change (Units)
1980	7.969
1981	4.279
1982	1.700
1983	4.628
1984	1.253
1985	-2.123
1986	3.522
1987	10.117
1988	2.156
1989	4.401
1990	-5.454
1991	0.945
1992	11.221
1993	7.365
1994	2.600
1995	5.685
1996	5.978
1997	8.885
1998	6.714
1999	5.940
2000	4.662
2001	2.460
2002	4.495
2003	-1.346
2004	2.570
2005	9.428
2006	9.174
2007	7.416
2008	3.210
2009	0.946
2010	8.340
2011	3.133
2012	2.717
2013	4.875
2014	7.050
2015	6.927
2016	6.659
2017	4.667
2018	6.983
2019	5.052
2020	-6.720
2021	12.272
2022	4.858
2023	2.409
2024	5.352
2025	4.952
2026	5.042
2027	5.042
2028	5.041
2029	5.042