This is the claim you sought to support. Within this very long document you have linked and handily not shortlinked or hinted at the source data, there is no conversation towards this end. Not surprising.
In fact, there is, on page 39, a table looking at some statistics using their defined measures: AllShort (all short trades), InstlShort (institutional shorts), RtlShort (retail shorts). This table holds the "mean" value of these items to be:
AllShort: 26.219% of volume
InstlShort: 26.045% of volume
RtlShort: 0.127% of volume
You have just shown the very opposite of what you claim amidst these extended length diatribes purporting that RobinHood and others are acting legally and in good faith all while acting as if you are very knowledgeable about the entire domain.
Sickening. Shill.