Year	Percent change (Units)
1980	72.433
1981	-0.197
1982	21.666
1983	32.605
1984	6.558
1985	-5.861
1986	7.628
1987	-0.620
1988	6.366
1989	25.369
1990	-7.563
1991	19.662
1992	13.544
1993	14.213
1994	8.813
1995	20.482
1996	19.262
1997	23.378
1998	4.135
1999	16.913
2000	-4.561
2001	14.040
2002	-0.368
2003	17.096
2004	24.757
2005	3.525
2006	9.587
2007	63.560
2008	19.244
2009	-34.168
2010	1.164
2011	36.330
2012	-0.661
2013	-6.431
2014	16.463
2015	8.195
2016	-1.172
2017	4.220
2018	22.012
2019	2.934
2020	-33.618
2021	27.494
2022	20.702
2023	-1.845
2024	0.060
2025	10.211
2026	2.876
2027	4.288
2028	5.311
2029	5.517