Allow more than one performance review to be open at one time for an employee

At end of year there is often a need to perform an end of year review on the current year performance whilst also setting up a new review for the following year and entering new goals / objectives. As you can only have one review open at any one time, currently this means you need to close off one before opening the new one. This means new year reviews are often added late and not from the start of the year therefore we would like the ability to be able to open a new one before the prior one is closed; effectively having multiple reviews open at one time