Year	Percent change
1981	20.67
1982	21.759
1983	17.871
1984	9.677
1985	5.882
1986	11.111
1987	3.75
1988	3.614
1989	4.651
1990	11.111
1991	10.614
1992	13.91
1993	4.373
1994	3.946
1995	5.706
1996	9.106
1997	0.395
1998	8.362
1999	-1.569
2000	-1.032
2001	4.562
2002	2.983
2003	-2.281
2004	-0.298
2005	1.759
2006	5.813
2007	3.378
2008	6.671
2009	-0.369
2010	3.426
2011	3.581
2012	4.149
2013	0.083
2014	-0.415
2015	-0.515
2016	-0.263
2017	0.345
2018	1.511
2019	1.6
2020	2
2021	2
2022	2
2023	2
2024	2