Year per Person 1970 2.45458 1971 2.36413 1972 2.61876 1973 2.75943 1974 2.73415 1975 2.82065 1976 3.19314 1977 3.27735 1978 3.46122 1979 4.32875 1980 2.66994 1981 2.92171 1982 2.18882 1983 2.29781 1984 2.37826 1985 2.17367 1986 2.80866 1987 2.21432 1988 3.0193 1989 3.50226 1990 1.79604 1991 0.22106 1992 1.23013 1993 2.74486 1994 3.2291 1995 5.18424 1996 5.13072 1997 4.86383 1998 4.65161 1999 3.97329 2000 4.21311 2001 4.05337 2002 3.65653 2003 4.14915 2004 4.44306 2005 4.86247 2006 4.69827 2007 4.04808 2008 4.3094 2009 3.66805 2010 3.52225 2011 3.81692 2012 4.11243 2013 4.07961 2014 3.57599 2015 3.86656 2016 3.80276