How can I keep my original data in submitted Forms

When I view my submissions, the original data specific to that client's contract is not there.  I modify the contract for each client and so when I go back to previous submissions the new data of my most recent client's contact is showing on the form.  The terms are different with each client.  How can I still view the data relevant to each clients contract.  

Keep in mind that deleting the form will also remove the form submissions to your form. If you delete a field, the data associated with that field will be removed.

You might want to download the form submissions before changing the form. Here's a guide: https://www.jotform.com/help/73-How-to-Download-Form-Submissions-as-Excel-CSV-PDF

You can also create multiple forms for each client. 

I hope this helps.