Year Percent 1961 0.46866 1962 1.94237 1963 3.94629 1964 0.99343 1965 2.33702 1966 3.57625 1967 0.86758 1968 2.04337 1969 3.25216 1970 1.13413 1971 9.67467 1972 7.49315 1973 11.54438 1974 45.88293 1975 4.95708 1976 7.3078 1977 9.8995 1978 7.33192 1979 18.96471 1980 25.99099 1981 12.86751 1982 3.73085 1983 6.59999 1984 14.60905 1985 10.45134 1986 2.90047 1987 33.28645 1988 21.7679 1989 88.68389 1990 41.74066 1991 21.44961 1992 28.24407 1993 31.64582 1994 62.89069 1995 51.7599 1996 115.52472 1997 38.42008 1998 18.89029 1999 26.19271 2000 29.45283 2001 7.9969 2002 33.02288 2003 34.93376 2004 33.95372 2005 29.60406 2006 17.90432 2007 15.44848 2008 30.13245 2009 7.83167 2010 45.94327 2011 28.14919 2012 14.05943 2013 35.50267 2014 40.44049