I'm searching for the way to create a combined graph line composed with month and year as dimensions.
In fact, i'd like to make a comparison of the staff with the payroll from January to December , each line representing a year.
Actually, i can get what i want but only with one expression. If i add another expression , i get what you can see in the attachments (what_i_get.jpg).
To make simple , i'll attach a picture of what i would like (what_i_want.jpg).