Look at this: https://upload.wikimedia.org/wikipedia/commons/1/1a/Boxplot_...
0.7% of all values are outside the whiskers.
The very Wikipedia article your image comes from explains this:
https://en.wikipedia.org/wiki/Box_plot#Whiskers
Look at this: https://upload.wikimedia.org/wikipedia/commons/1/1a/Boxplot_...
0.7% of all values are outside the whiskers.