Year	Percent change (Units)
1980	4.515
1981	1.598
1982	0.235
1983	3.973
1984	6.052
1985	5.553
1986	4.042
1987	1.754
1988	-0.255
1989	1.038
1990	1.932
1991	3.084
1992	3.574
1993	2.845
1994	5.055
1995	4.156
1996	5.028
1997	5.285
1998	2.669
1999	2.072
2000	3.319
2001	2.067
2002	1.378
2003	0.945
2004	4.015
2005	2.685
2006	2.461
2007	2.914
2008	0.482
2009	-1.940
2010	0.787
2011	1.106
2012	2.718
2013	1.016
2014	2.048
2015	1.857
2016	1.165
2017	2.464
2018	0.829
2019	1.124
2020	-1.278
2021	3.909
2022	3.006
2023	0.514
2024	1.525
2025	1.918
2026	1.700
2027	1.582
2028	1.396
2029	1.423