What's the most effective approach for report testing?

I have came across more than 100 reports needs to be tested in a short period of time? I came up with a approach by prioritising the reports based on business risks with the follwoing method. However, I would like to hear from anyone that have a more effective way of testing reports?

The method I use - basedline testing for Existing report

create a backup of the test data generate report before changes deployed restore the test data rerun the same report after changes occur

New report: create a backup of the test data after changes deployed, write simple sql query to modify test data from backend or to generate report from front end