In Greece, there are no large scale violent protests, unless it is an organized strike/peaceful march, which are typically quite uneventful. These organized strikes/peaceful marches were more common in previous years and do not happen now, as there is a leftist government in power. There are some occasional isolated clashes between certain "anarchist" type anti-authority small groups with police, that never involve citizens, but sometimes may involve limited destruction of public property. They are usually confined in very specific locations of political significance, such as the Polytechnic School, and often take place very late at night. Even in those clashes there are almost never deaths and rarely some injuries among those actively involved. There have never been large scale riots or protests in Greece that turn violent, with significant injuries or deaths.

Despite a sustained unemployed rate of 27% for several years now, and a reduction of standard of living by approximately 40-50%, the social fabric is still relatively strong with no substantial increase in violent crime (there is some, mostly occasional burglaries in remote locations, and petty theft). Tourists are never targeted, as far as I know, never heard of a case. There is no major organized gang activity and there are no guns in the streets.
I am not aware of official statistics though.