Year	Percent change (Units)
1980	19.079
1981	10.858
1982	7.359
1983	10.244
1984	6.402
1985	10.649
1986	3.280
1987	-11.449
1988	4.105
1989	6.924
1990	21.276
1991	15.420
1992	19.358
1993	22.556
1994	42.557
1995	30.200
1996	20.584
1997	11.606
1998	6.591
1999	2.794
2000	6.446
2001	15.489
2002	6.555
2003	22.238
2004	25.710
2005	14.111
2006	12.972
2007	6.913
2008	12.511
2009	5.597
2010	2.921
2011	5.242
2012	5.699
2013	5.299
2014	3.155
2015	5.317
2016	11.435
2017	10.610
2018	11.416
2019	17.308
2020	22.945
2021	15.941
2022	27.576
2023	44.100
2024	23.013
2025	14.276
2026	12.450
2027	11.514
2028	11.514
2029	11.514