I claim the ornamental design for a eighteen-year photograph frame, as shown and described.
FIG. 1 is a front elevational view of an eighteen-year photograph frame embodying the novel design, the rear elevational view being a mirror image of the front elevational view;
FIG. 2 is a top plan view thereof;
FIG. 3 is a side elevational view of one side thereof;
FIG. 4 is a side elevational view of the other side thereof; and,