CT database does not show all records

I have used CT for many research projects. I have a problem with a CT database that seems to have lost most of its records. My colleague has previously copied alot of data from this CT database, to a spreadsheet, so we know that the database did contain the full set of records but we dont seem to be able to access most of them now when looking in report mode (no filters). We are certain that we haven’t accidentally deleted lots of records and then saved the database. I have opened the database using CT Desktop 3.529 and also, on another laptop, version 3.531. Is there something obvious that I am missing here?

If you have no older version of your database, I think the data are lost. The older version of CT does not help.