Year per Person 1970 1.52026 1971 1.43672 1972 2.82249 1973 11.78648 1974 24.50535 1975 30.82804 1976 39.07885 1977 43.16456 1978 40.79291 1979 41.27766 1980 40.08786 1981 37.62401 1982 36.47733 1983 36.96685 1984 36.36122 1985 34.45696 1986 33.57983 1987 32.56432 1988 32.88909 1989 31.32629 1990 31.04121 1991 30.62259 1992 32.03717 1993 32.98302 1994 32.30118 1995 35.61671 1996 34.43726 1997 33.65295 1998 30.36758 1999 30.96948 2000 30.51245 2001 30.15727 2002 29.73186 2003 31.46391 2004 30.62113 2005 29.60089 2006 30.55503 2007 29.42134 2008 28.84098 2009 26.7685 2010 28.44116 2011 29.23508 2012 28.29032 2013 27.07805 2014 25.90939 2015 25.05137 2016 23.84474