Best Selling Categories with woocommerce

I am trying to get the top 4 most popular categories, meaning the categories returned should have the most sales? What arguments do i have to change in my WP_Query?

Here is my WP_Query, this returns the best selling products but i want best selling categories.

$args = array( 'post_type' => 'product', 'per_page' => '24','posts_per_page' => '18','meta_key' => 'total_sales','orderby' => 'meta_value_num');
$args['meta_query'] = $woocommerce->query->get_meta_query();

$loop = new WP_Query( $args );

How do i solve this?

https://wordpress.org/plugins/woocommerce/