[Dxbase] ITU Zones

[Gary AL9A]

Need some help understanding which ITU zone IL is in.  I'm setting up TQSL 
station locations from my old IL QTH to upload into LOTW.  The TQSL program 
wants to know the CQ Zone, ITU Zone and Grid Locator.  I know the CQ Zone is 
3, I think my old grid was EN51 (Elburn, IL), but have a problem with the 
ITU Zone number.  My old logs show Midwest stations as being in ITU Zone 6, 
but when I look up ITU maps on the internet they all show ITU Zone 6 as 
being on the west coast - WA, OR and CA???  Did they change the map or have 
I always had the wrong ITU zone set up in DXBase?

73,
Gary AL9A