Looking for a way to have data continue to add without having multiple data sheets.

I am looking for a way to track recruitment activity on a weekly/monthly/quarterly/annual basis but I don't want multiple sheets with data, and I was hoping there was a way from me to input data in the fields highlighted in yellow and for the column next to it to just keep adding the numbers to tally up monthly, quarterly and annual numbers.

Formatting or how the spreadsheet looks can change, but it's more the usability and ability of the spreadsheet to track numbers.

I'm a very basic excel user so I'm not really sure which function/formula would work best. Would be seeking for advice from all you expert excel users!

Thank you!!