Year	Percent change (Units)
1980	25.699
1981	21.267
1982	-7.894
1983	18.832
1984	18.851
1985	2.227
1986	-18.773
1987	19.350
1988	17.130
1989	0.154
1990	-7.689
1991	3.459
1992	14.251
1993	12.525
1994	7.670
1995	10.425
1996	2.738
1997	11.297
1998	3.705
1999	8.255
2000	10.815
2001	9.166
2002	8.729
2003	15.561
2004	17.193
2005	9.864
2006	3.383
2007	5.484
2008	-2.190
2009	-10.424
2010	8.544
2011	2.966
2012	-0.314
2013	3.058
2014	-2.102
2015	8.798
2016	4.032
2017	7.223
2018	4.360
2019	-2.030
2020	0.038
2021	4.100
2022	5.417
2023	8.123
2024	2.664
2025	3.701
2026	3.152
2027	2.610
2028	2.246
2029	1.749