number of distinct values in tsearch2 gist index

In the output of gist_stat() in the gevel contrib module, is the number
of tuples the number of distinct values stored in the index? Is the
number (6M) so large because the positions are part of the values? I'm
guessing I can't determine the number of distinct lexemes from the
output of gist_stat() ....

select gist_stat('idxfti_idex');
gist_stat
------------------------------
Number of levels: 5
Number of pages: 244881
Number of leaf pages: 234515
Number of tuples: 6017003
Number of invalid tuples: 0
Number of leaf tuples: 5772123
Total size of tuples: 1846434636 bytes
Total size of leaf tuples: 1779845516 bytes
Total size of index: 2006065152 bytes

(1 row)

Time: 193023.012 ms

Thanks,
Kevin Murphy