Year % of total 1971 0 1972 0 1973 0 1974 0 1975 0 1976 0 1977 0 1978 0 1979 0 1980 0 1981 0 1982 0 1983 0 1984 0 1985 0 1986 0 1987 0 1988 0 1989 0 1990 0 1991 0 1992 0 1993 0.1558654284166035 1994 1.2906214264603346 1995 1.0247187961774344 1996 1.0584087105598428 1997 1.005973515589097 1998 0.9577741190567797 1999 0.9584444891964253 2000 0.9840079167363815 2001 0.9452682562634828 2002 1.2279086963931147 2003 1.8594315842613982 2004 1.9021164072988983 2005 1.7848280409869375 2006 1.6282955029700574 2007 1.6276942063848308 2008 1.700148404956052 2009 1.6274601855221535 2010 1.5250128546758632 2011 1.604419163321824 2012 1.70434294902191 2013 1.7991980232751628 2014 2.0463385366443303