Mexico join Wassenaar Arrangement

According to Wassenaar Arrangement ("WA") web site, Mexico joined WA effective Jan 25, 2012.
Mexico is 41st participating state of WA.

http://www.wassenaar.org/publicdocuments/2012/Public%20Statement%20on%20Mexico.pdf

Then, the interest of Japanese trader would be whether Mexico is treated as "White Country" or not, which is the country group WMD catch-all screening is exempted. 
The answer is No.  One of the requirements to be White Country is to be a participating state of ALL four international regimes, NSG, AG, MTCR and WA.  Mexico is not participating in NSG, AG, and MTCR.