The word suicide, like the word homicide, tells you who caused the death -- not what caused the death. Comparing numbers of suicides to numbers of actual causes of death misleads readers. I can think of only 3 other categories that we can legitimately categorize with suicide: murder, deaths from accidents, deaths from chronic toxic exposure, and deaths from natural causes. Chronic toxic exposure would include tobacco and alcohol use and exposure to asbestos or coal dust. Of these, only suicide and murder are intentional. We should also remember that some murderers use chronic toxic exposure to kill their victims.
Actual causes of death might include overdose, bleeding, drowning and infection. Consider, for example, that more than half of deaths from gunshot wounds are suicides. A large number are homicides, and the rest are accidental.