Year per Person 1970 3.18473 1971 4.74879 1972 4.03895 1973 3.93279 1974 3.31803 1975 2.69517 1976 2.69885 1977 4.69178 1978 6.02984 1979 5.77602 1980 6.49281 1981 7.11393 1982 7.18762 1983 6.0045 1984 7.50866 1985 8.55971 1986 9.30433 1987 9.73975 1988 9.43564 1989 10.44507 1990 9.72973 1991 10.87752 1992 9.56227 1993 9.37345 1994 10.38096 1995 11.51085 1996 11.83188 1997 12.10329 1998 11.75521 1999 11.59274 2000 10.9486 2001 12.16044 2002 11.13442 2003 10.77278 2004 10.19122 2005 9.39195 2006 8.37671 2007 7.4885 2008 6.55848 2009 5.7336 2010 5.58043 2011 5.42832 2012 5.49073 2013 5.4562 2014 5.38207 2015 5.91667 2016 6.00629