public static function get_order_totals() {
		global $wpdb;

		$gross_total = $wpdb->get_var(
			"
			SELECT
				SUM( order_meta.meta_value ) AS 'gross_total'
			FROM {$wpdb->prefix}posts AS orders
			LEFT JOIN {$wpdb->prefix}postmeta AS order_meta ON order_meta.post_id = orders.ID
			WHERE order_meta.meta_key =  '_order_total'
				AND orders.post_status in ( 'wc-completed', 'wc-refunded' )
			GROUP BY order_meta.meta_key
		"
		);

		if ( is_null( $gross_total ) ) {
			$gross_total = 0;
		}

		$processing_gross_total = $wpdb->get_var(
			"
			SELECT
				SUM( order_meta.meta_value ) AS 'gross_total'
			FROM {$wpdb->prefix}posts AS orders
			LEFT JOIN {$wpdb->prefix}postmeta AS order_meta ON order_meta.post_id = orders.ID
			WHERE order_meta.meta_key =  '_order_total'
				AND orders.post_status = 'wc-processing'
			GROUP BY order_meta.meta_key
		"
		);

		if ( is_null( $processing_gross_total ) ) {
			$processing_gross_total = 0;
		}

		return array(
			'gross'            => $gross_total,
			'processing_gross' => $processing_gross_total,
		);
	}