my %bins;
open my $INF, '<', $FileName or die $!;
while (<$INF>) {
    chomp;
    $bins{get_bin($_)}++;
}
printf "%-6.6s %u items\n", $_, $bins{$_} for sort keys %bins;

sub get_bin {
   # Determine the name of the bin to put the value into
   my $val = shift;
   my $bin_min = int($val / 10);
   my $bin_max = $bin_min + 10;
   return "$bin_min-$bin_max";
}