Year % of total 1960 56.81818181818181 1961 34.6613545816733 1962 22.49240121580547 1963 121.84873949579833 1964 54.97584541062802 1965 43.33098094565984 1966 65.18987341772153 1967 62.92490118577074 1968 75.77132486388385 1969 78.77934272300469 1970 39.81255093724532 1971 43.07692307692308 1972 43.861209964412815 1973 37.0269215762778 1974 31.667274717256475 1975 30.182926829268293 1976 23.64724844577481 1977 28.043527544774427 1978 36.578947368421055 1979 37.82065336549002 1980 42.563325395107164 1981 38.24091778202677 1982 39.40298507462687 1983 47.413405308142146 1984 44.29109159347553 1985 45.459363957597176 1986 42.69141531322506 1987 44.474675596483884 1988 45.204529697249825 1989 58.973194002726025 1990 76.25072997873848 1991 83.49476923076922 1992 93.19651299245598 1993 88.42557337610265 1994 89.92880952380953 1995 87.5788829787234 1996 99.31228571428571 1997 100.36981118373276 1998 115.15940425531915 1999 128.6675721323012 2000 136.61873259052925 2001 146.2284575502268 2002 154.09640449438203 2003 179.352682767624 2004 186.08245460237944 2005 171.1950228774784 2006 171.4017191719172 2007 180.97400996828276 2008 183.2112298959319 2009 193.75708766716195 2010 185.86275419982317 2011 178.8907761966365 2012 183.5986663652803 2013 180.83327320721511 2014 188.40216240875912 2015 191.9569285042333 2016 207.36754251234234