Commission Rate in admin WC Vendors->Commissions table

Hello,

I am setting different commission rates for each of my vendors’ products and I want to add a column with the commission rate (i.e. just the percentage) in the admin WC Vendors->Commissions table, for keeping better evidence purposes.

Here’s a printscreen: https://prntscr.com/kz0fuh.

Thus, I am editing wc-vendors/classes/admin/class-wcv-commissions-page.php, but I am not able to figure out what to return for the commission rate.

Please see below:

/**
	 * column_default function.
	 *
	 * @access public
	 *
	 * @param unknown $item
	 * @param mixed   $column_name
	 *
	 * @return unknown
	 */
	public function column_default( $item, $column_name ) {
		global $wpdb;
		switch ( $column_name ) {
			case 'id' :
				return $item->id;
			case 'vendor_id' :
				$user = get_userdata( $item->vendor_id );
				return '<a href="' . admin_url( 'user-edit.php?user_id=' . $item->vendor_id ) . '">' . WCV_Vendors::get_vendor_shop_name( $item->vendor_id ) . '</a>';
			case 'total_due' :
				return wc_price( $item->total_due );

			case 'commission_rate':
			  
				return ????????;

                        [..........]

Please take a minute from your time and help me out with this.

Thank you for your support!