Year	Percent change
1980	19.629
1981	11.853
1982	14.397
1983	15.06
1984	11.57
1985	14.988
1986	15.694
1987	12.035
1988	12.401
1989	14.671
1990	11.967
1991	17.3
1992	18.095
1993	10.678
1994	8.304
1995	9.724
1996	8.89
1997	8.376
1998	8.237
1999	7.774
2000	6.06
2001	7.965
2002	12.212
2003	6.343
2004	4.641
2005	3.645
2006	6.337
2007	9.177
2008	10.688
2009	5.832
2010	3.307
2011	6.005
2012	5.467
2013	5
2014	4.565
2015	4.3
2016	6.206
2017	4.516
2018	5.2
2019	5.4
2020	5.6
2021	5.5
2022	5.5
2023	5.5
2024	5.5