Annual % of total
1960 82.16503992901508
1961 80.57190916736752
1962 81.32358911896061
1963 80.13270882123341
1964 77.85858585858585
1965 41.6935636985001
1966 54.54665784248842
1967 36.90191387559809
1968 47.38701878370839
1969 44.53808752025932
1970 47.79141104294478
1971 43.361707533985516
1972 48.442734830624154
1973 42.21610625822664
1974 41.68049300782176
1975 37.8234903782349
1976 46.0775473399459
1977 51.996644295302005
1978 46.70710571923743
1979 44.592069752958274
1980 47.963618802318095
1981 69.0068493150685
1982 66.56687821817746
1983 74.40143844042775
1984 68.11382707041226
1985 64.3765903307888
1986 64.73659960067579
1987 68.4349212953332
1988 74.94601597927014
1989 75.26531838205848
1990 51.25318118735544
1991 84.497025871285
1992 79.59767918088737
1993 64.62793173369381
1994 64.32417326782313
1995 69.8332643080125
1996 63.50981164732234
1997 52.37168926504879
1998 78.95349005646943
1999 95.97993654233092
2000 82.78165213892986
2001 89.39128113879005
2002 97.87440498677749
2003 118.37369034406215
2004 126.93011953778723
2005 99.03352147795535
2006 85.67989867683872
2007 45.199668258680774
2008 73.45507322175733
2009 65.82660621279763
2010 66.08712966813607
2011 75.87552774173854
2012 74.56909456077966
2013 75.44026268840356
2014 73.869938403222
2015 74.70786176706332
2016 82.76973252103278