Of course, nothing is forever and the terms of trade have been falling for about five years now, and are down from the peak by about a third (though they are still about 20 per cent above that very long-run average).
Overall, then, the past decade has been a much more volatile time, from the external point of view, than either of the two preceding decades. This is easily demonstrated with some simple metrics for the growth and variability of the world economy, and Australia's terms of trade. The tables show data for four decade-long periods.