I agree. I did the best I can by using the median over all flights from the past 12 months. But yes, there are a lot of irregular operations which can throw an

I agree. I did the best I can by using the median over all flights from the past 12 months. But yes, there are a lot of irregular operations which can throw any conclusions to the wind. That said, when I was exploring this data I found that delays etc were much less frequent that I perceived.