This sounds like it would be a good use of a cross-tab.
Cross-tabs can only be placed in a Report Header/Footer and/or a Group Header/Footer.
When placed in the Report Header/Footer, the cross-tab will contain a summary for ALL records retrieved from the database.
When placed in the Group Header/Footer, the cross-tab will contain a summary for just the records that are in the group. One cross-tab would be generated for each group that appears.
To create a cross-tab, first decide where it is going to be placed. If there are already objects in the section where you want the cross-tab, then create a new section below that one. This new section will be used to hold the cross-tab.
On the Insert menu, choose Cross-tab. Depending on your version, you'll either get a Cross-tab Expert(v10 and prior) or you'll get an object attached to your mouse cursor(v XI).
If it's v XI, drop the object into the proper section, and then right-click it in the upper left corner and select "Cross-tab Expert"
If it's V10 or prior, you're already there.
From the "Available Fields" list, choose a field for your summarized field, choose a field for your Column (you said 'Year') and choose a field for you Row (you said month)
If both Year and Month are from Date or DateTime type fields, you'll need to click the "Group Options" button just below the 'Rows' and 'Columns' boxes and select the appropriate breakout for the date.
When you're finished, click the OK button.
If this is v10 or prior, you'll have the cross-tab object attched to your mouse cursor. Move to where you want to place your cross-tab and left-click to drop it in place.
If this is v XI, it's already in place and you're good to go.
Whenever you want to edit the contents of your cross-tab, right-click in the upper left corner of the object, in the "Dead Zone" where there are no cells, and choose "Cross-tab Expert".
Bob Suruncle