Year	Percent change
1980	19.19
1981	12
1982	9.524
1983	13.768
1984	19.745
1985	10.638
1986	14.183
1987	25.053
1988	33.838
1989	12.453
1990	11.857
1991	8.227
1992	23.236
1993	22.775
1994	34.659
1995	83.148
1996	37.733
1997	9.137
1998	29.779
1999	44.759
2000	29.597
2001	7.641
2002	7.714
2003	7.827
2004	7.976
2005	8.16
2006	8.337
2007	8.516
2008	8.716
2009	8.416
2010	7.409
2011	7.621
2012	21.296
2013	28.279
2014	23.775
2015	21.86
2016	21.727
2017	11.541
2018	9.215
2019	8.657
2020	8.154
2021	7.136
2022	6.15
2023	5.324
2024	4.982