How can I adjust the Age of sample population?

Question

[debitboro]

Dear (bio)-statisticians;

How can I adjust the age of the samples according to the standard population? I've a dataframe describing my data as follows:

Age          Count (cases)           population
[10,14]             200                 6041
[15,19]             142                 5098
[20,24]             131                 3233
[25,29]              92                 2223