How should I normalize the grade of a movie by users ( y)?

Question

I have two datasets.The first one contains the grade of users mark for a movie(y). The second dataset shows that if the users have rated the moive or not(r) ( if the users have rated the movie => r =1 , otherwise r = 0). I don't know how should I normalize with two variables y and r. Will it be wrong if I use this formula : $$y mean = \frac{y - y min }{ymax-ymin}$$