I made a spreadsheet in Excel that shows how many times any given pair of last digit numbers were drawn together. Unfortunately I cant get it into The Lottery Post without it losing all of it's formatting. When I pasted it in here, it became scrambled and becomes usless. I made the spreadsheet for all drawings of Sweet Million since it began in September 2009.
But I can tell you that the 9/39 pair is the top pair, having been drawn together fifteen times.
Here's the first section of the spreadsheet
1 11 21 31
11 8 X
21 7 6 X
31 7 7 6 X
1 paired withh 11 eight times, it paired with 21 seven times, and it paired with 31 seven times.
I dont know if anyone will find this helpful or not, but I thought I'd go ahead and post it anyway.