Year	Percent change (Units)
1980	64.220
1981	9.356
1982	3.675
1983	9.695
1984	0.912
1985	-9.752
1986	-0.816
1987	3.651
1988	-0.327
1989	18.092
1990	-3.609
1991	9.762
1992	20.303
1993	16.647
1994	8.838
1995	20.779
1996	19.786
1997	21.120
1998	4.977
1999	15.860
2000	-3.447
2001	13.727
2002	0.031
2003	14.252
2004	23.639
2005	7.276
2006	6.151
2007	60.033
2008	19.768
2009	-28.182
2010	0.124
2011	33.981
2012	1.099
2013	-3.209
2014	16.093
2015	12.597
2016	3.223
2017	7.353
2018	15.133
2019	3.062
2020	-35.960
2021	29.570
2022	22.420
2023	-2.718
2024	-0.488
2025	11.567
2026	3.967
2027	4.879
2028	5.430
2029	5.570