my %categories = ();
	while (  my $name = <$dataIn1>)
	{
     	chomp($name);
     	my ($file, $category) = split(/\t/, $name);
     	if (exists($categories{$category}))
     	{
      	 $categories{$category} += 1;
    	 }
     	else
     	{
      	 $categories{$category} = 1;
   	  }
}
foreach my $category (sort { $categories{$b} <=> $categories{$a} } keys %categories) {
  printf "%s: %s\n", $category, $categories{$category};
}

##</code><code>##

something like:
my $score = $subres->[2]
Foreach $category in $categories {where %subres [0] = $category} ($score = ($subres [1] / ($categories{$category}))