The person choosing the starting date helps choose the story the trend will tell.

Where a chart begins is an argument, not a neutral fact. Start in a bad year and everything looks like recovery; start in a good one and the same figures look like decline. Nobody has to lie for this to work, which is why it is so common and so hard to object to. The numbers are genuine and the conclusion was decided before they were plotted.

When you see a trend, look at the axis before the line and ask why the window is that window. And when you present your own figures, choose the range you would have chosen if the answer had come out the other way.