They last longer if frozen.
If it's not in a sealed, vac sealed container, they deteriorate as soon as it's opened. If you can smell hops when you open the door, that's aroma that's no longer in your hops. Specifically regarding your question, well, it's a slow deterioration- some Nelson Sauvin I had in my fridge not well sealed for about 3 months had a noticeable decline in aroma qualities, but they were still there.
So, it's a lot of 'it depends'. I recommend that if you are going to store a lot of hops in the freezer to get a vac sealer, I was incredibly happy when I bought it.