Year	Percent
1982	44.77633
1983	47.13343
1984	49.56008
1985	46.8617
1986	45.19213
1987	49.01323
1988	42.44803
1989	44.27346
1990	42.46675
1991	43.87187
1992	45.47672
1993	44.35896
1994	52.0969
1995	48.95238
1996	39.89355
1997	37.16689
1998	36.82538
1999	36.86497
2000	35.70901
2001	36.90603
2002	36.14027
2003	37.7059
2004	36.91781
2005	39.58013
2006	40.02278
2007	40.29913
2008	38.73946
2009	46.19815
2010	44.47569
2011	45.20665
2012	45.10226
2013	44.45609
2014	45.45963
2015	46.40344
2016	46.47998
2017	46.79085