Cumulative total

Hi Experts,

i am looking for a cumulative sum based on combination on Period and Week for example 

this is the output i am looking for

My Current DAX is 

YTD Charged Hours =

CALCULATE(

    SUM('YTD Timesheet'[Hours]),

    'YTD Timesheet'[H Category] = "Chargeable"

)

 

i want to modify this pls note that 

i am using a Calendar table  with one to many relationship with Charged Hours table using Week Coloumn