Queries :: Analyze Multiple Fields Of Actual Vs Estimated Expenses

I am trying to find the best way to compare estimated expenses to actual expenses in Access. I am working with vessel and port call information, so each port call has a series of costs associated with it. I have two tables, each with multiple fields (around 100). Each of the fields contains a cost type that goes to a particular cost code. Each row of the table is associated with one particular port call. The call is estimated right after it happens, but the invoices are not all recieved for up to three months. Once all of the invoices for this port call have been recieved, we enter the actual expenses for the call. I am trying to find the best way to analyze the costs through finding the variances for one particular port call for each code, and also for multiple port calls to see which cost item has the largest/smallest variance for further investigation into how to estimate it more accurlately. I am thinking that I may have to move into Excel to do this, but would like to stay in Access if possible.