Year	Percent
1990	60.53336
1991	61.98777
1992	60.18066
1993	59.63716
1995	65.28307
1996	65.35327
1997	65.57306
1998	57.34374
1999	65.72587
2000	62.48808
2001	62.18785
2002	52.2037
2011	63.40589
2012	62.89584