In which year did the author Q. Wu publish the most research papers?
Mention the year in which Qianteng Wu published the most papers.
SELECT (GROUP_CONCAT(?answer; separator=', ') AS ?answer) ?count WHERE { SELECT DISTINCT ?answer (COUNT(?answer) AS ?count) WHERE { ?x <https://dblp.org/rdf/schema#authoredBy> <https://dblp.org/pid/215/6855> . ?x <https://dblp.org/rdf/schema#yearOfPublication> ?answer } GROUP BY ?answer } ORDER BY DESC(?count) LIMIT 1
<https://dblp.org/pid/215/6855>