[natnat]

When you're looking at a line chart that starts at zero, it's very difficult to really understand what's going on unless there's a really huge amount of variability in the data. For example, charts of stock prices virtually never start at zero. Does that mean that, say, Google Finance is trying to deceive you into thinking that Apple's price went up ten times today? No, it means that they're assuming that you're not stupid and that you know how to read a chart. NASA very clearly labels the chart, and anyone who isn't astoundingly stupid or willfully trying to misunderstand the data can see very clearly that this chart starts at 160.