How to store the result of which postcode has the most occurrences of illness? I create a table contain postcode and the occurrences of themselves. But I don't know what to do next

this is the head 5 rows of dataset enter image description here
How to store the result of which postcode has the most occurrences of illness? I create a table contain postcode and the occurrences of themselves. But I don't know what to do next

this is the head 5 rows of dataset enter image description here
I made sample data dummy, as.table(c(2,1,1,1,2,3)) which is like
A B C D E F
2 1 1 1 2 3
Simply using which.max(), which.max(dummy) prints
F
6
in your case, which.max(ill2) is what you want