XY Scatter Plot - Multiple Values Per Month

I was given a printout and asked to create a similar chart to track prices on a weekly basis. Not sure how to list multiple values per month, with some months having 5 weeks and others having 4.

I've attached the spreadsheet I've come up with so far based off of the 2009 series (I'm guessing I'm WAY off), as well as the image I'm working from. (I unfortunately can't be given a copy of the excel file it was created from, which would solve my problem easily).

I'm in a bit over my head with this one.
Thanks in advance!