[-] BO : Stats are empty when no conversion rate

install-dev/upgrade/sql/1.5.6.1.sql

@@ -1 +1,3 @@
 ALTER TABLE `PREFIX_customer_message` CHANGE `ip_address` `ip_address` VARCHAR( 15 ) NULL DEFAULT NULL;
+
+UPDATE `PREFIX_orders` SET conversion_rate = 1 WHERE conversion_rate = 0;