Year	Percent change (Units)
1980	7.383
1981	5.462
1982	4.058
1983	3.093
1984	4.167
1985	2.888
1986	2.167
1987	2.168
1988	5.068
1989	-0.816
1990	7.363
1991	-6.156
1992	7.382
1993	2.511
1994	-4.007
1995	5.630
1996	-0.525
1997	4.402
1998	0.014
1999	2.724
2000	-0.967
2001	5.444
2002	4.616
2003	1.971
2004	3.100
2005	5.745
2006	-1.829
2007	0.804
2008	3.965
2009	3.241
2010	3.778
2011	4.144
2012	3.168
2013	4.466
2014	2.107
2015	1.147
2016	3.320
2017	3.816
2018	3.642
2019	1.761
2020	-0.196
2021	2.000
2022	2.603
2023	2.996
2024	3.491
2025	4.027
2026	4.328
2027	4.484
2028	4.311
2029	3.813