Year	Percent change
1987	33.654
1988	26.259
1989	26.068
1990	27.331
1991	12.233
1992	16.1
1993	4.996
1994	2.543
1995	5.2
1996	2.053
1997	5.291
1998	4.529
1999	6.161
2000	7.207
2001	1.13
2002	6.118
2003	12.094
2004	27.644
2005	29.663
2006	39.132
2007	12.822
2008	13.504
2009	7.899
2010	20.803
2011	19.026
2012	12.833
2013	10.548
2014	8.968
2015	7.324
2016	8.701
2017	9.546
2018	9.6
2019	8.6
2020	8.1
2021	8
2022	7.9
2023	7.8
2024	7.8