I have been using Jira to keep record of the time spent in particular issue in a specific sprint. 
After selecting the attributes and the sprint (say Sprint 2), I export my Jira report in excel form(csv) but I get to see that the time spent in particular issues have been cumulative for some issues(say, issues which were already in Sprint 1 and continued in Sprint 2).
But I need only the report for Sprint 2 and the actual time spent on issues, and not the cumulative time spent on some issues.