The issue being that you're looking at two things which are riots. When the words "Mostly peaceful" are used they are referring to the thousands of other BLM/ANTIFA protests (the message relating to issues of police brutality) which didn't end in violence. Of that data set, 92% were peaceful from the movement which is/was comprised of 25 million people at the time. In June, of that 25 million headcount, only 14k were arrested which results in a total of 00.07% of protesters are violent relating to that issue.
So far, for the issue involving Mike Pence not doing what Trumpers wanted him to do, there has been one protest. Of that protest, it has turned violent. Making 100% of protests involving this issue 100% violent.