AV 2006 Virus Defs Folder is 13.3GB

There are several similar posts but I can not find a solution.

I have been losing 100MB or more of space almost every day.  Now getting very short of free space.  Found that program files\common\Symantec Shared\Virus Defs is over 13 GB of my 40GM drive.  Not good.  Several hundred folders with dates as far back as 2006, some days there are several folders, not every date.  Some folders say they are empty, many are 100MB or more.  Which ones do I need?  Surely AV can not require 14GB!

 

What is the solution?