You'd need to compare them against other carriers on like routes at similar times from the same ports. If they are equally delayed, then we are likely to have systemic issue at those ports at those times. Though, having seen how many other carriers handle their departures, I wouldn't be surprised if this was a QF-specific issue in the close peer group (e.g. all carriers flying AU-US or AU-SG) - and if it is, it's a fair go to point that out.
