Year	Percent change (Units)
1980	6.994
1981	8.041
1982	10.425
1983	8.022
1984	3.304
1985	4.138
1986	-1.419
1987	0.653
1988	1.917
1989	3.925
1990	4.359
1991	2.599
1992	2.904
1993	3.608
1994	1.803
1995	1.258
1996	1.320
1997	1.500
1998	0.418
1999	2.393
2000	4.326
2001	0.974
2002	2.825
2003	2.466
2004	3.519
2005	3.513
2006	2.271
2007	4.333
2008	0.721
2009	2.499
2010	3.081
2011	3.376
2012	2.433
2013	1.503
2014	-1.000
2015	0.808
2016	1.553
2017	1.569
2018	1.943
2019	1.963
2020	-0.178
2021	5.619
2022	6.357
2023	3.243
2024	1.713
2025	3.292
2026	2.182
2027	1.876
2028	2.059
2029	2.059