Annual % of total
1960 92.15017064846415
1961 90.9090909090909
1962 90.27459954233409
1963 90.35532994923858
1964 92.52728799328295
1965 90.5284147557328
1966 93.51230425055928
1967 93.39697692919651
1968 92.25092250922509
1969 90.78481012658227
1970 87.77533039647578
1971 90.38382170862566
1972 88.76298394711992
1973 89.96748722712495
1974 91.38846737481032
1975 91.90163934426229
1976 89.2324093816631
1977 88.84721180295074
1978 88.12334377258492
1979 92.27516669377134
1980 91.43310417768376
1981 92.09801762114537
1982 90.79065588499552
1983 90.11147540983606
1984 90.55851063829786
1985 89.43853574078653
1986 90.4561403508772
1987 80.33201741066911
1988 81.3498759305211
1989 79.38680246127731
1990 96.05878254988163
1991 100.06307692307692
1992 100.0016592356688
1993 106.55281534460339
1994 103.10849435382686
1995 96.29548530721283
1996 90.27534365661505
1997 87.82045491251682
1998 86.22256928838952
1999 91.80569755600814
2000 88.21022767518339
2001 83.13346489104117
2002 54.738642533936655
2003 89.0730605487228
2004 76.13867278424351
2005 63.78337589928058
2006 65.06229134795173
2007 82.71410817772055
2008 82.67636746799874
2009 76.44542089249492
2010 66.79222445561139
2011 68.04147353361945
2012 63.062193955207654
2013 77.24361939076319
2014 70.4139859623199
2015 72.04443932411674
2016 74.65657218442932