What’s the data source? If they’re just doing news reports and traditional history that can hide a lot of failed non-violent protests. A non violent protest, especially one against the medias interests, is way less likely to show up in the historical record then a violent insurrection. Only the successful movements like the civil rights movement will get mentioned on the non-violent side whereas every insurrection or riot, successful or not, is captured in the historical record.

What’s the breakdown by method? It seems they’re including strikes in this which has a very high success rate and high occurrence, so much so it could drown out all the failed protests.