Help with dates and a graph!!

[#1]

Hi everybody.

I'll atach a very simple example of what i have to do. I have propertys,  the money of the rental and the date of the rental.

I have to show with all the months as a dimension in what months the renter payed and in what months didnt pay.

If i don't have date and money the renter didn't pay. If i have date and money the renter payed.

I have to show this in %. For example if the renter payed all the months i have all blue, if not i have a part in red color ,etc.

The first problem is that i don't have dates for the months that the renter didn't pay, i've been trying to use some thing but they aren't working.

I read an article with variables, but sometimes i don't have the last date to do a max - min, because i don't have the last months.

Thank you!!

[Gysbert_Wassenaar]

Maybe like attached qvw.