It's do simple that countries who have higher population will have more peoplein them, more people means that more love/hate relationship, more love thena fine but love is not in air these days (in fact it never was in any part of the world) that means more heat will be there, and that hate results in more attacks and more attacks causes more murders.
This poll should have given result in terms of % of Population i.e. % Murder = (Total no. of Murders/ Total Population of that country)
