I found that 80% number strange and it seems the real numbers are much more complex than that: http://en.wikipedia.org/wiki/Gender_differences_in_suicide

The entry paragraph gives a quick glimpse of the complexities but here's my attempt at a tl,dr of it:

- there are highly asymmetric rates of attempted and completed suicide between genders

- can vary significantly between different countries

- males die much more often by means of suicide than do females

- reported suicide attempts and thoughts are much more common among females than males

- females have a higher rate of attempted suicide than males earlier in life, which decreases with age

- for males the rate of attempted suicide remains fairly constant when controlled for age

- genders tend to differ in their methods of suicide and responses to suicidal feelings