Drupal legends are legendary
I got this graph from drupal.org. It made me laugh out loud. It shows you which versions of Drupal, one of the more popular off-the-shelf content management systems, are used the most.
For some reason the webmasters of drupal.org decided to split the then current major version, 8, into all its medium versions. If you just looked at the legend, you might be forgiven for believing that Drupal 8 is very popular. (It is not.)
Below is the graph contrasting the popularity of major Drupal versions against the space they receive in the legend.
Note that I copied the top graph in March of this year. In the meantime, Drupal 9 has become the official current version.