For example, before we decide that the last 5 years are a good average we should look at what the trend of the last 5 years looked like. If for example there was an upwards trend (which it was for many countries around the world) then even without COVID you'd expect that 2020 would have continued on that trend for whatever reason it was going that way. In that case it would be fairly unexciting to say that 2020 was above the 5 year average in the context of COVID.

In my opinion the fairest comparison would be to check if 2020 continued the trend of the last 5 years, or if it had a non linear jump upwards from that trend, but looking at figures such as "above average" doesn't mean anything if every year in the last 5 years was "above average" because it started to trend upwards again.