The query *is not exact* on at least two reasons: 1) dupe closures initiated by flags aren't counted, the first actual close voter is counted instead 2) it is not sure that the first close voter voted for the post as dupe (he was just the first of the close-voters, whose majority of the voters voted for dupe).
Q&A for biology researchers, academics, and students
SELECT TOP 10 *
WHERE PostHistoryTypeId = 10 AND Comment IN (1,101);
--SELECT * FROM CloseReasonTypes;