FIG. 1 is a use state diagram of a sunken refrigerator shelf showing my new design;
FIG. 2 is a front, right, top perspective view thereof;
FIG. 3 is a folded state diagram;
FIG. 4 is a folded use state diagram;
FIG. 5 is an enlarged front view thereof;
FIG. 6 is a left view thereof;
FIG. 7 is a right view thereof;
FIG. 8 is an enlarged back view thereof;
FIG. 9 is a top view thereof;
FIG. 10 is a bottom view thereof;
FIG. 11 is an enlarged view of the encircled area 11 of FIG. 1;
FIG. 12 is an enlarged view of the encircled area 12 of FIG. 1;
FIG. 13 is an enlarged view of the encircled area 13 of FIG. 2;
FIG. 14 is an enlarged view of the encircled area 14 of FIG. 2;
FIG. 15 is an enlarged view of the encircled area 15 of FIG. 3;
FIG. 16 is an enlarged view of the encircled area 16 of FIG. 5;
FIG. 17 is an enlarged view of the encircled area 17 of FIG. 6; and,
FIG. 18 is an enlarged view of the encircled area 18 of FIG. 10.
The broken lines shown on the drawings depict portions of the sunken refrigerator shelf that form no part of the claimed design.