How long does a negotiation stays listed in the Abstract listing page

Summary:

Hi everyone!
For the negotiations that are posted to the Abstract listing page of the organization; for how long do the negotiations stay listed on the page?
I understand that the abstract listing can be removed by going into the negotiation and selecting the option of 'Remove Abstract'.

But if this option is not exercised by the user; will the negotiation stay always on the Abstract page?

Is there a way to control the removal of closed negotiations from the Abstract page?
It wouldn't make any business sense to keep the negotiations on the Abstract page if they are already closed.