In chart 1, we show the full range from 0-100%, which makes the change in percentage of the data seem smaller. In chart 2, the scale ranges only from 40-80%, which makes the full change in percentage seem larger. Even though the percent change is the same in the second chart, the change appears to be much more dramatic (larger) because of the scale of the chart. One can be mislead if they are not checking the scale values carefully.