Is there a way to know if a Sharepoint 2013 farm was upgraded from earlier versions

Question

We are working on a new project with one of our customers, and they have on-premise SharePoint server 2013 with SP1 and January 2016 cumulative update installed. But i am trying to know the history of this SharePoint farm, and if it was upgraded from earlier versions of SharePoint such as 2010 or 2007, or it is a SharePoint 2013 from day one.

now our customer do not have the answer,, so not sure if there is a way to know if this SharePoint 2013 server is 2013 from day one or it is upgraded from 2010 or from 2007 ? Thanks

EDIT

now i run the following command, on our web application's content database, and i got the following :-

now as shown above all the versions starts with 15, so does this mean that it is a 2013 database from day one ? second question i can not find any version which represents the following number 15.0.13.0 what does this represents ?

Answer 1

The farm couldn't have been 'upgraded', but the databases certainly could have. For the Content Databases, you can run the following T-SQL query:

SELECT * FROM Versions (NoLock)

That will tell you the version history in the Version column.