Year	Percent change (Units)
1980	12.020
1981	8.154
1982	15.874
1983	10.793
1984	6.517
1985	7.695
1986	8.616
1987	14.890
1988	23.420
1989	4.665
1990	8.787
1991	6.237
1992	-0.208
1993	4.027
1994	-0.786
1995	8.453
1996	2.466
1997	7.106
1998	-1.622
1999	8.035
2000	4.271
2001	2.348
2002	7.434
2003	5.388
2004	1.397
2005	4.972
2006	6.034
2007	5.793
2008	3.252
2009	-14.144
2010	10.122
2011	6.839
2012	-0.171
2013	11.103
2014	5.697
2015	-4.851
2016	7.202
2017	4.113
2018	4.190
2019	3.033
2020	-8.726
2021	11.867
2022	5.782
2023	3.245
2024	3.574
2025	4.593
2026	4.011
2027	3.992
2028	4.023
2029	3.979