Year	%
1984	50.98611
1985	47.61678
1986	49.48398
1987	57.25405
1988	61.73506
1989	73.22991
1990	89.70419
1991	82.39838
1992	88.37498
1993	86.45414
1994	92.86951
1998	96.26281
1999	96.43883
2000	95.92073
2001	96.82726
2002	97.76683
2003	97.47313
2004	99.02993
2005	98.51813
2006	97.66237
2007	98.56675
2012	97.46923