https://www.macrotrends.net/countries/AUS/australia/suicide-rate
Suicide is difficult to measure. Many serious traffic accidents where the driver doing something stupid are thought to be suicide. and this is a preferred method for some. drug overdoses too might be suicide as most IVDUs know their tolerance and keep within their normal range. These days there are many different drugs can be used for suicide purposes.
and this data being collated by the World Bank would related to definite suicides, leaving a note, very clear intentional use of violent means, such as using a rope or firearm.
but you can see the general increase in suicide from a low in 2004 at 4.7 per 100k population to at least 10 per 100k in 2019.
I don't say that all would be associated with robodebt. there is no data I've been able to find that addresses this question.
