Year	Percent change (Units)
1980	12.867
1981	23.369
1982	26.890
1983	68.526
1984	66.575
1985	76.576
1986	80.867
1987	178.700
1988	34.287
1989	60.800
1990	110.946
1991	102.695
1992	65.500
1993	22.202
1994	24.199
1995	25.987
1996	23.137
1997	14.559
1998	35.986
1999	34.092
2000	-0.918
2001	2.568
2002	0.121
2003	3.991
2004	12.922
2005	13.702
2006	10.533
2007	16.978
2008	8.211
2009	7.469
2010	7.186
2011	6.791
2012	6.588
2013	5.524
2014	4.639
2015	6.689
2016	10.886
2017	18.222
2018	16.030
2019	14.805
2020	13.447
2021	11.874
2022	27.209
2023	47.716
2024	39.118
2025	21.740
2026	15.150
2027	11.350
2028	8.900
2029	7.500