Partitioning on multiple columns?

I'm working a personal project and I have this table called Movies, Formatted as such:

And I split it up by genre into a table as below because
I want to count the number of genres create per Release Year:

To do that I tried to partition it by two columns 'Genre' and 'Release_Year' using this Query:

Select Genre, Count(Genre) OVER (Partition by Genre,Release_Year) as Num_genre, Release_Year
FROM Movies

My Expected outcome is a table as such:

However when I run that query I end up getting a lot of dupes (same genre same year same count) back and it ends up looking like this:

Results

Any help would be really appreciated thanks!

Use the GROUP BY aggregation clause:

SELECT
  Genre,
  COUNT(1) AS Num_genre,
  Release_Year
FROM
  Movies
GROUP BY
  Genre,
  Release_Year
;