Year	Percent
1990	22.89212
1991	26.81545
1992	24.96892
1993	26.39628
1994	24.28637
1995	25.24727
1996	24.25333
1997	27.00872
1998	26.00619
1999	28.27759
2000	27.52385
2001	26.38772
2002	25.96844
2003	23.172
2004	24.28142
2005	25.75505
2006	29.13719
2007	30.90927
2008	30.08916
2009	29.44724
2010	25.91213
2011	29.98128
2012	32.93275
2013	31.53882
2014	33.64857
2015	32.50059
2016	28.53354