How to subtract a group of variables from a column

Dear Community, 

I am a new user and working on my first dashboard in Power BI. The file I got has data in weekly frequentcy from different departments, these are all sorted on date. One column is the amount of employees from the department on that specific date, I want to calculate what the total amount of workers is on that date and how many percentage of the total employees are working for that department.

So I want 

Total Employees on that date 

Percentage of employees working for that department on that date 

Thanks in advance,

0xygen27