My question involves landlord-tenant law in the State of: Chicago, Illinois

I informed the leasing office of my apartment building that I would be moving out of my apartment more than 60 days ago. I was unable to find a tenant to sublet it and now no longer live in the apartment. When I told the leasing office that I would be moving out they told me that they would attempt to find a tenant to sublet the apartment. However during the 60+ days from which I notified them they did not show my apartment to one potential tenant nor did they have the apartment listed on Zillow or Craigslist. I was told that I could break the lease however I would have to pay two months rent just to break it so I decided to attempt to find someone to sublet the apartment.

Since I did not tell the leasing office that I wanted to break the lease and rather I just gave them written notice that I would be moving out and needed to find a new tenant, are they still required by law to make a "reasonable effort" to re-rent the apartment to a new tenant?