Annual % of total
1960 8.514647935583348
1961 5.8757221361138505
1962 5.660979110189762
1963 7.001448575567358
1964 5.3872605207139355
1965 3.0892618446457747
1966 3.8401253918495297
1967 2.5231412361899075
1968 1.714741459524126
1969 1.6802108499890185
1970 1.2079025488791073
1971 1.4202407825432655
1972 1.2099162365682374
1973 0.7239346219867154
1974 0.858430502897203
1975 1.0125033976624085
1976 0.7237778832463219
1977 0.6183274021352313
1978 0.5816677076826984
1979 0.6863841437550611
1980 0.7466728567007119
1981 0.7908032510800322
1982 0.8175334840841887
1983 1.1424778142687444
1984 1.680122903932272
1985 3.0304863295427054
1986 6.623693484743518
1987 6.666864819878731
1988 5.235703781804056
1989 4.7991040179196425
1990 4.6980417595783495
1991 8.360868759268412
1992 7.324988590486221
1993 11.498421393142118
1994 13.542929467323415
1995 11.306747890863399
1996 11.763550835892186
1997 11.414990879807506
1998 12.292608562456921
1999 13.333111581060253
2000 14.996782667666059
2001 19.50314779842958
2002 20.668959354374962
2003 19.6071932492471
2004 22.652134864203287
2005 25.738208768873406
2006 30.61506893710519
2007 33.891618769408915
2008 45.93423537833395
2009 43.99581991938959
2010 31.042060008634337
2011 38.45137160221454
2012 39.48306173600411
2013 17.477009816869167
2014 8.466164268952149
2015 31.268563686741096
2016 43.20419128045578