What year did an NFL team not lose a game all year?
1972 Miami dolphins
1939
1939
1932
2008
2007
1939
2006
2005
2008
2000
1932
2010
2007
2012
2006
2001
2004
1939
2009
1926
1931
2005
2002
1970
2008
2000
2010
2007
1972
2012
1987
2006
2001
1932
2004
2011
1976
2009
2017
1923
2005
1927
2002
1970
1939
2008
2000
1921
1926
2013
2003
1922
1931
2010
2007
1999
1972
2012
1924
1987
2006
2001
1998
2004
2016
2011
1976
2009
2017
2014
1967
1986
1932
2005
1985
2002
1970
2008
2000
1996
1997
2013
2003
1923
1927
2010
2007
1999
1972
2012
1939
1921
1926
1987
1922
1974
2015
1931
1995
1994
2006
2001
1998
1980
2004
2016
1977
2011
1988
1924
1976
2009
2017
2014
1973
1967
1986
2005
1985
2002
1984
1970
1982
2008
2000
1996
1997
2013
2003
1932
2010
1969
2007
1999
1972
2012
1975
1979
1987
1974
2015
1995
1994
1978
1923
2006
2001
1927
1998
1980
2004
2016
1939
1977
2011
1988
1976
2009
1921
1926
2017
2014
1973
1967
1922
1966
1931
1986
2005
1985
2002
1983
1984
1990
1970
1989
1982
2008
1924
2000
1996
1997
2013
2003
1968
2018
2010
1969
2007
1999
1972
2012
1992
1975
1993
1979
1987
1974
2015
1995