On the initial view, only the 40th to 60th percentiles are shown. On subsequent views, only the 25th to 75th percentiles are shown. There are many above those ranges, including some outliers with 3% or more of their company (choose Scientist > Fellow for one example).

Also, according to the Source line at the bottom, executives and founders are excluded from the data set. Getting a large share of equity of a private company is rare for everyone else.