Thank you.
We understand that your time was at a [STRIKE] permium[/STRIKE] premium.
We understood that your time was at a [STRIKE]permium[/STRIKE] premium.
As I said, it depends on both the rest of the sentence, which you have provided, but also on the context. When is the sentence said? What timeframe does it refer to? The choice of tense is impossible to decide if you post two perfectly grammatical sentences (which they now are) but we don't know anything else.
Don't forget a full stop (or relevant punctuation mark) at the end of every sentence.