return me the number of papers published in PVLDB in each year .
SELECT COUNT ( DISTINCT t2.title )  ,  t2.year FROM publication AS t2 JOIN journal AS t1 ON t2.jid  =  t1.jid WHERE t1.name  =  "PVLDB" GROUP BY t2.year;
SELECT COUNT ( DISTINCT t2.title )  ,  t2.year FROM publication AS t2 JOIN journal AS t1 ON t2.jid  =  t1.jid WHERE t1.name  =  "PVLDB" GROUP BY t2.year;
[{'Nenhum': 'Nenhum resultado encontrado'}]