Add column in backend of products for sales count with multi currency

Hey there,
i added a column with total sales in the backend for products.
The problem is, the code only sums up the sales for the orders in €, and doesnt include the sales for orders in $. How can i sum up all sales in all currencies?
I use the plugin CurrencySwitcher and this is my snippet:

add_filter( 'manage_edit-product_columns', 'misha_total_sales_1', 20 );

add_action( 'manage_posts_custom_column', 'misha_total_sales_2' );

add_filter('manage_edit-product_sortable_columns', 'misha_total_sales_3');

add_action( 'pre_get_posts', 'misha_total_sales_4' );
 
function misha_total_sales_1( $col_th ) {
 
	return wp_parse_args( array( 'total_sales' => 'Total Sales' ), $col_th );
}
 
function misha_total_sales_2( $column_id ) {
 
	if( $column_id  == 'total_sales' )
		echo get_post_meta( get_the_ID(), 'total_sales', true );
}
 
function misha_total_sales_3( $a ){
	return wp_parse_args( array( 'total_sales' => 'by_total_sales' ), $a );
}
 
function misha_total_sales_4( $query ) {
 
	if( !is_admin() || empty( $_GET['orderby']) || empty( $_GET['order'] ) )
		return;
 
	if( $_GET['orderby'] == 'by_total_sales' ) {
		$query->set('meta_key', 'total_sales' );
		$query->set('orderby', 'meta_value_num');
		$query->set('order', $_GET['order'] );
	}
 
	return $query;
 
}