How to create cumulative sum based on a parent Item

I have 2 tables Actors and Movies. Actor have fields like Actor name, Dob. Movies have fields like Boxoffice Collections, Movie name, Cumulative collections. Actor and Movies have one to many relationship. One Actor many Movies.  I want to get the cummilative collection based on the Actor-actor name in the child table Movies. 
Example:
Actors

Actor Name	DOB
Williams	04-Mar
Jason	05-Jun

Movies

Movie name	BoxOffice Collection	Actor Name	Cummilative Collections
One Night	10	Williams	10
At the call center	25	Williams	35
Kumbalangi	20	Jason	20
Roja	30	Williams	65
Chichore	15	Jason	35

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Aswin Babu
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