The chart on the left shows that most tornadoes are weak, either F0 or F1. Only 1% of all tornadoes fall into the violent F4-F5 category, but they account for 67% of all tornado-related deaths. Conversely, the 74% of tornadoes that are weak F0-F1 account for only 4% of tornado-related deaths. Tornadoes as a whole are very infrequent, but deadly tornadoes are even more infrequent.