Annual % of total
1960 97.24137931034483
1961 96.73202614379083
1962 96.66666666666669
1963 96.95652173913044
1964 96.91119691119691
1965 95.77464788732394
1966 95.80152671755725
1967 95.59322033898304
1968 95.83333333333331
1969 95.72649572649573
1970 95.56135770234987
1971 96.10705596107056
1972 96.34703196347031
1973 94.78957915831663
1974 93.98496240601504
1975 95.43726235741444
1976 94.89291598023064
1977 95.99483204134368
1978 96.23955431754875
1979 97.43040685224838
1980 96.20253164556962
1981 96.06164383561644
1982 97.5736568457539
1983 97.43589743589743
1984 97.22772277227722
1985 97.42173112338858
1986 97.73095623987034
1987 97.89473684210527
1988 97.71615008156606
1989 95.53349875930522
1990 101.08
1991 98.16864583333333
1992 100.67879464285714
1993 98.84231818181817
1994 94.35640316205533
1995 98.80143396226414
1996 95.57606382978723
1997 97.86761589403973
1998 91.88335227272727
1999 97.47590395480226
2000 92.79358090185677
2001 94.3342748091603
2002 92.6685221674877
2003 87.58706401766004
2004 92.57137777777778
2005 94.3186511627907
2006 93.26050997782706
2007 92.97062098501071
2008 93.23717488789237
2009 96.56154897494305
2010 93.9109756097561
2011 95.09599580712788
2012 91.87046908315565
2013 91.38915367483295
2014 90.98165966386554
2015 94.56267552182163
2016 97.46858736059481