Year	Percent change (Units)
1980	3.360
1981	6.222
1982	-0.643
1983	2.404
1984	12.062
1985	7.580
1986	11.223
1987	10.883
1988	-1.729
1989	0.495
1990	4.155
1991	-4.447
1992	13.502
1993	13.298
1994	15.493
1995	6.911
1996	7.985
1997	12.629
1998	5.994
1999	7.978
2000	25.390
2001	-4.979
2002	0.728
2003	3.555
2004	15.629
2005	2.583
2006	4.235
2007	9.549
2008	3.499
2009	-12.766
2010	15.932
2011	5.546
2012	-4.136
2013	2.529
2014	1.017
2015	-4.710
2016	-1.359
2017	0.705
2018	2.456
2019	1.530
2020	-1.209
2021	6.971
2022	3.773
2023	-0.570
2024	-0.223
2025	6.977
2026	4.198
2027	3.432
2028	3.400
2029	3.444