Postgres 9.4 unlogged table. Under any circumstance after server crash would data persist?

Hi,
The goal was to minimize log activity during ETL. The assumption was, once a Table load was "committed" the data would persist after a system shutdown.
Our database backup currently "aborts" the server (working to change to an orderly shutdown).
I have loaded data to an unlogged table, and committed on completion.
I am able to see the data in another session, so I am sure the data has been persisted.

Over night, our database is shut down (forced) for a backup. The next morning, I find that the data in my unlogged table is gone.

Is there any case where this data, in an unlogged table, would persist through a server "crash"? (however caused).

Thanks,

STeve

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