Year	Percent
1987	32
1988	37.03704
1989	35.71429
1990	36.66667
1991	37.28814
1992	79.4375
1993	15.46906
1994	18.57798
1995	19.06442
1996	16.90726
1997	28.50983
1998	30.38942
1999	26.36119
2000	28.89527
2001	29.76286
2002	33.86163
2003	36.21581
2004	38.19019
2005	42.93808
2006	45.60734
2007	42.29037
2008	27.2152
2009	27.00056
2010	28.14354