Year	Percent change (Units)
1980	12.293
1981	-0.641
1982	-8.486
1983	-3.258
1984	7.078
1985	3.527
1986	5.359
1987	12.225
1988	17.784
1989	11.430
1990	8.563
1991	6.723
1992	7.529
1993	3.241
1994	9.572
1995	11.646
1996	8.897
1997	14.479
1998	2.173
1999	4.196
2000	9.809
2001	-6.430
2002	-3.455
2003	2.894
2004	8.992
2005	7.618
2006	10.062
2007	6.996
2008	5.871
2009	-11.862
2010	15.182
2011	7.469
2012	3.954
2013	2.932
2014	4.472
2015	-0.334
2016	0.647
2017	4.136
2018	4.233
2019	0.169
2020	-10.049
2021	7.616
2022	5.762
2023	2.557
2024	2.011
2025	3.372
2026	2.992
2027	3.002
2028	2.903
2029	2.766