how many nfl shutouts in 1997
how many nfl shutouts in 1996
how many nfl shutouts in 1995
how many nfl shutouts in 1994
how many nfl shutouts in 1993
how many nfl shutouts in 1992
how many nfl shutouts in 1991
how many nfl shutouts in 1990
how many nfl shutouts in 1989
how many nfl shutouts in 1988
how many nfl shutouts in 1987
how many nfl shutouts in 1986
how many nfl shutouts in 1985
how many nfl shutouts in 1984
how many nfl shutouts in 1983
