Chart not showing total amounts correctly

I have a table with the following columns

Name | Group | MonthsRemaining

I have a chart to display the total number of students we'll have every month for the next 12 months and the problem that I run into is that chart won't display anything when there are months with no graduations.

My current measure looks like this:

CALCULATE(
    COUNTROWS(Name), 
    ALLEXCEPT(Student, Student[Group])
) - 
CALCULATE(
    COUNTROWS(Name),
    FILTER(ALLEXCEPT(Student, Student[Group]), Student[MonthsRemaining] <= MAX(Student[MonthsRemaining]))
)

Any help will be greatly appreciated.

Thank you!