How many people did the Cartwrights kill on bonanza?

It was claimed that the Good Guys, the Catrwright bros, never fired their weapons in anger on Bonanza, there was gunplay but it was done by bad guys and police/western Marshals, etc) one can draw an analogy to the television version of Dragnet. in the entire run of the show, Sergeant Friday never fired his revolver and seldom drew it. Dragnet deliberately de-emphasized gunplay.