How can I add new rows in my table and chose the values in these new rows?

Hello,

I have the feeling that I want to do something very simple, and probably the answer is simple as well 😅 But I just don't know how to accomplish the following:

I have a column named Period with the following values

2017-01

2017-02

2017-05

2017-06

2017-09

2017-10

2017-12

How can I add rows with the missing periods, so that I obtain the following table:

2017-01

2017-02

2017-03

2017-04

2017-05

2017-06

2017-07

2017-08

2017-09

2017-10

2017-11

2017-12

I don't necessarily need to automate this. So I am ok with typing in the new values (2017-03, 2017-04, 2017-07, 2017-08, 2017-11) in a transformer. But which transformer do I need for this?

Thanks in advance,

Eva