Year	Percent change (Units)
1980	5.403
1981	-12.255
1982	-26.587
1983	3.227
1984	14.319
1985	-5.268
1986	-2.802
1987	-3.033
1988	17.907
1989	1.244
1990	-2.846
1991	6.000
1992	7.475
1993	7.072
1994	-2.735
1995	8.608
1996	2.291
1997	-1.394
1998	7.542
1999	4.417
2000	3.499
2001	8.487
2002	1.906
2003	0.646
2004	5.593
2005	5.711
2006	5.571
2007	14.101
2008	1.921
2009	-20.691
2010	9.121
2011	10.756
2012	1.115
2013	-0.769
2014	4.741
2015	18.104
2016	1.486
2017	2.915
2018	2.627
2019	-0.983
2020	-8.438
2021	22.325
2022	4.147
2023	-3.314
2024	4.604
2025	4.384
2026	4.289
2027	3.926
2028	3.795
2029	2.981