Year	Percent change
1980	15.429
1981	16.337
1982	8.085
1983	13.126
1984	50.826
1985	5.656
1986	-0.336
1987	7.047
1988	9.566
1989	15.248
1990	18.178
1991	13.187
1992	7.767
1993	6.907
1994	8.427
1995	8.29
1996	6.699
1997	6.278
1998	10.127
1999	4.023
2000	6.262
2001	4.506
2002	2.653
2003	3.877
2004	8.398
2005	6.743
2006	4.435
2007	3.861
2008	8.055
2009	4.358
2010	3.626
2011	4.136
2012	2.749
2013	3.766
2014	1.91
2015	0.75
2016	2.233
2017	2.912
2018	5.128
2019	3.5
2020	3.1
2021	3
2022	3
2023	3
2024	3