Acceptance checkbox – value

In my form I insert a acceptance checkbox like this
<p> [acceptance accept-this default:on] Example text</p>

When I receive the email with the data that people enter the form I receive this data
Example text: 1

I wish that instead of the value 1 appeared “yes” (if the box has been checked) and “no” if the box will be unchecked.

How can I do that?

https://wordpress.org/plugins/contact-form-7/