Using Excel 2003

I have created a spreadsheet to track sales. However, when I go to my
yearly tab to look at year-to-date percentages, the percentages reflect
yearly data instead of year-to-date data.
For example, we are in January and one of my sales teams is over 100%,
however YTD figures is only reading 9%.
How can the YTD cells reflect true YTD information rather than calculating
data for the entire year.

Thanks!
Matthew