To count the occurrance of things in your array:

my @array = ('foo', 'foo', 'bar', 'foo', 'bar', 'baz');
my %count;
$count{$_}++ for @array;

for(sort(keys(%count))) { 
    print "$_: $count{$_}\n";
}
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I'm sure you can work out how to then calculate the percentages.