Q&A for linguists, teachers and learners wanting to discuss the finer points of the Portuguese language
select DataYear, DataMonth, cnt, prev, round(100-cnt*100.00/prev,2) prc from ( select datayear, DataMonth, cnt, lag(cnt) over (order by datayear, DataMonth) prev from ( select year(creationdate) as DataYear, month(creationdate) as DataMonth, count(*) as cnt from posts where posttypeid between 1 and 2 group by year(creationdate), month(creationdate) ) as a ) as b where cnt<prev order by DataYear, DataMonth