There seems to be some disconnect between your document and data. Your document refers to '2012 Premium Rates' but there's nothing apparently related to those in the workbook. And, where there are figures for 2013 & 2014, it's by no means apparent which of the four sets of rates for each year you want to use and which one go where. Then there's the schedule you have going back to 1988, for which there appears to be no data.

Also, FWIW, your Sheet2 is unnecessary for a mailmerge - any difference in formatting that you might require between the data and the document can be handled by field switches in the document.