OK like you guys suggested I used del_lf_rows_len and lf_rows_length and below is the result that I got.

Deleted Used % Deleted
Index Name Leaf Rows Leaf Rows Leaf Rows
------------------------------ --------- --------- ----------
PK_NEWSTABLE 0 1613 .00000


QUESTION: From the above results what is the best way to determine if the index needs to be rebuild?