Year	Percent change (Units)
1980	25.156
1981	69.600
1982	95.401
1983	49.487
1984	64.897
1985	91.602
1986	453.538
1987	360.357
1988	374.354
1989	95.770
1990	36.031
1991	81.817
1992	37.705
1993	8.379
1994	10.378
1995	16.926
1996	5.593
1997	3.095
1998	8.110
1999	4.093
2000	-1.784
2001	-0.439
2002	3.765
2003	3.110
2004	7.812
2005	8.300
2006	7.664
2007	8.377
2008	23.311
2009	6.693
2010	9.140
2011	18.685
2012	9.121
2013	6.592
2014	4.087
2015	0.647
2016	2.675
2017	3.521
2018	3.540
2019	2.795
2020	3.220
2021	1.837
2022	3.157
2023	3.253
2024	3.740
2025	3.433
2026	3.390
2027	3.390
2028	3.390
2029	3.390