234 



G. H. KNIBBS. 



This corrected frequency relation, obtained by thus 

 deducing the rate for each sex separately, has been com- 

 puted for the period 1861 to 1910, for Australia, and the 

 annual average number of males and females per 10,000,000 

 of each sex committing suicide for each quinquennium was 

 found to be as shewn in the following table, in which the 

 ratio of frequency of suicides of males to suicides of females 

 is also shewn. These average annual rates per quinquen- 

 nium are deduced for each sex by dividing the sum of the 

 suicides in a quinquennium by the sum of the mean annual 

 populations of the respective sex. 1 The ratio m/f denotes 

 the true relative frequency of suicide in the two sexes. 



Average Annual Number of Male and Female Suicides per 

 10,000,000 of each sex in Australia to 1910. 



Period. 



Frequency 



Male 



Suicides. 



Frequency 

 Female 

 Suicides. 



Batio. 



m/f 



Period. 



Frequency 



Male 

 Suicides. 



Frequency 

 Female 

 Suicides. 



Ratio. 

 m/f 



1861 - 1865 

 1866 - 1870 

 1871 - 1875 

 1876-1880 

 1881 - 1885 



1677 

 1547 

 1545 

 1631 

 1517 



391 

 341 

 392 

 360 

 333 



4-29 

 4 54 

 394 

 453 

 455 

 Mean 



1886 - 1890 

 1891-1895 

 1896 - 1900 

 1901 - 1905 

 1906-1910 

 4-317 



1783 

 1843 

 1911 

 2094 

 1813 



433 

 444 

 479 

 410 

 435 



412 

 4-14 

 3 99 

 4-89 

 4-71 



The difference between the values for individual 5-year 

 periods and the mean give no indication of any systematic 

 trend, and may be regarded as accidental. The relative 

 frequency 4'317 may, therefore, be regarded as constant, 

 and as the proper (corrected) frequency of male suicides as 

 compared with female in Australia. 



4. Variation of frequency with age for each sex.— Since 

 the constitution of a population, in respect of the numbers 

 of each sex for corresponding age-groups, differs with each 

 country and even in the same country at different periods, 

 comparisons of the suicides within the various age-groups 



1 The numbers for individual years are somewhat irregular, so that it 

 was deemed desirable to group them in quinquennial periods. 



