Year	Percent change (Units)
1980	11.240
1981	26.846
1982	6.673
1983	1.653
1984	5.516
1985	1.066
1986	4.766
1987	16.039
1988	8.760
1989	7.748
1990	4.759
1991	6.469
1992	4.058
1993	3.566
1994	2.303
1995	2.230
1996	0.926
1997	2.813
1998	3.556
1999	1.999
2000	2.538
2001	3.578
2002	1.964
2003	3.016
2004	1.419
2005	1.199
2006	2.041
2007	3.935
2008	4.842
2009	4.297
2010	2.763
2011	0.874
2012	1.347
2013	1.459
2014	0.799
2015	2.483
2016	0.842
2017	3.067
2018	2.381
2019	2.713
2020	5.346
2021	2.343
2022	6.679
2023	12.041
2024	7.631
2025	6.004
2026	4.402
2027	3.915
2028	3.915
2029	3.915