> And I rolled it over 30 days to be able to show any recent changes while not getting lost in the noise of daily change.
small thing, but learned at work that often there's a weekly pattern (and I'd bet there is for airplane travel) so you ought use a rolling 7 day average instead of 30 because there are different numbers of weekends in each day's 30 day number.
This is why there's a slight zigzag in the line charts in the article.
One fun one is that in a lot of year on year change reporting for China specifically, Jan-Feb is considered a single month and then all the other 10 months are seperate. Reason is:
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The dates of Chinese New Year move around across the year and they have such a big effect on the stats that it's easier just to lump the two months together.
small thing, but learned at work that often there's a weekly pattern (and I'd bet there is for airplane travel) so you ought use a rolling 7 day average instead of 30 because there are different numbers of weekends in each day's 30 day number.
This is why there's a slight zigzag in the line charts in the article.