Meaning for Sales-CRM Pipeline fact "# of New Opportunities"

Summary

I am looking for the definition of "New" for the Sales-CRM Pipeline fact "# of New Opportunities".

Content

When pulling this Fact into my analysis today, I am seeing Opportunities created from June 7 of the current year to the present date of 9/4/2018.  Can anyone tell me explicitly what the definition of this Fact is?  Is it any opportunities created within a rolling 3 months period?  Is it for Opportunities created based on Enterprise Months, or Calendar months, or number of days?  What is the meaning of New?

Thanks,

John

Version

R13