The right way to question for many seen posts and present high 5

Right here is how I get the views for one submit:

perform getPostViews($postID){
        $count_key = 'post_views_count';
        $rely = get_post_meta($postID, $count_key, true);
        if($rely==''){
            delete_post_meta($postID, $count_key);
            add_post_meta($postID, $count_key, '0');
            return "0 View";
        }
        return $rely.' Views';
    }

For instance I wish to discover essentially the most seen posts from 5,000 posts and I wish to present the highest 5 most seen posts.

How can I make a question to realize this?