Year	Percent change (Units)
1980	5.920
1981	3.051
1982	6.279
1983	5.307
1984	8.837
1985	4.746
1986	3.583
1987	7.139
1988	8.317
1989	8.088
1990	7.402
1991	0.740
1992	9.365
1993	0.701
1994	5.899
1995	9.924
1996	1.248
1997	2.641
1998	6.111
1999	4.998
2000	5.966
2001	3.951
2002	3.723
2003	2.624
2004	5.025
2005	4.855
2006	4.714
2007	5.096
2008	3.648
2009	-2.016
2010	2.283
2011	0.417
2012	-3.448
2013	-6.587
2014	-1.775
2015	3.417
2016	6.574
2017	5.734
2018	5.648
2019	5.537
2020	-3.443
2021	9.910
2022	5.059
2023	2.460
2024	2.689
2025	2.876
2026	2.955
2027	3.079
2028	3.071
2029	2.982