Making Columns One...Continued

Hi,

I am trying to find the difference between the last cell of data for a given month and the last cell of the current month's data. I would like to be able to format the data such that there is one column of data with a value for each month over x number of years in sequential order. However, I am having trouble with the way my data is formatted.

I currently have my data formatted so that it has columns of daily values where each of the columns are months of the year, but these columns are stacked upon each other so that Oct of 2000 is continuous with Oct of 2001, 2002... etc.

Is there a way I can do this? Please see the attached to get a sense of the format.

Thanks!

Thanks again. I'll see what I can do with that. In the meantime does anyone else have any thoughts on finding the difference between the value of the last day of a month and the value of the prior month's last day?

Thanks!