22 
Over 50 per cent of the cases occurred among persons who had 
resided in the District of Columbia all their lives. So this year, as 
in 1907, the disease does not seem to have prevailed to any veiy 
unusual extent among newcomers. 
However, it should be noted that in both years the number of 
cases among persons who had resided in the District less than 5 years 
is much larger than (nearly tvdce) the number among persons who 
had resided in the District from 5 to 10 years, and over three times 
as large as the number among those who had resided in the District 
from 10 to 15 years. 
In considering these figures it should be remembered that the 
transient element of Washington’s population is rather large, and 
that among persons having resided here less than 10 years there is 
of course a large proportion of children. 
PREVALENCE. 
The following table shows the cases according to dates of definite 
onset : 
Onsets hy days. 
