Dos and Don’ts of Data Visualisation
Choose your chart
Bar chart: do use the full axis and avoid distortion
For bar charts, the numerical axis (often the y-axis) must start at zero.
Use the full axis for bar charts. Our vision is very sensitive to the area of bars and we draw inaccurate conclusions when those bars are truncated.
If you need to show data details that are not visible when using the full axis, then the original chart with full axis can be accompanied with a 'zoomed-in chart', a so called 'panel chart' in Excel. See example below:
More reading
Making these charts interactive will solve many of the issues stated above. For example, the user would be able to mouse-over a column and get the exact value, filtering out some categories or sorting the columns according to their values for easier comparison.