Year	Percent
1991	24.7772
1992	23.72798
1993	22.74414
1994	21.8655
1995	20.92642
1996	20.08492
1997	19.15756
1998	18.26995
1999	17.47521
2000	16.74731
2001	15.96331
2002	15.43441
2003	14.91145
2004	14.45786
2005	14.07383
2006	13.58874
2007	13.19819
2008	12.82744
2009	12.5702
2010	12.3907
2011	12.08884
2012	11.80262
2013	11.50644
2014	11.259
2015	10.97118
2016	10.72744
2017	10.46998
2018	10.21199
2019	9.96883