Year	Percent
1991	14.61279
1992	14.02873
1993	13.48061
1994	12.55603
1995	11.77074
1996	11.14043
1997	10.77121
1998	12.02349
1999	11.3438
2000	10.60276
2001	9.95716
2002	9.33279
2003	8.8055
2004	8.39855
2005	7.95788
2006	7.64835
2007	7.30037
2008	7.14291
2009	7.00622
2010	6.60063
2011	6.37153
2012	6.1331
2013	6.757
2014	5.58368
2015	5.23338
2016	4.93928
2017	4.92282
2018	4.9957
2019	5.14028