The number 30 was used by myself for very good reasons.  You yourself have stated that 29 matrix schemes are still operational - a figure drawn I believe from the matrixwatch.org website.  As my own matrix scheme - www.cyberama.net - is operational but classified as non-operational by matrixwatch.org (why I do not know!), then 30 must be the minimum number of matrix schemes operational currently.  As stated before, this is a conservative number - I personally believe that there are far more but this would be unverifiable without some intense work verifying all known matrix scheme domains.   

 To include the number of matrix sites that have ceased trading would be hard if not impossible - there is no proof that any domains that would be claimed by anyone were ever matrix schemes.  If domains have expired, there is no evidence that either they ever existed or what their content consisted of.  Therefore, I feel it is unverifiable to state any given number of matrix schemes that may have ceased trading.  Stating that many have ceased trading is the best solution, in my opinion.   

 In my mind, the term "operational" regarding a website would mean that it was viewable and that it is possible for it to operate.  Therefore, any matrix scheme that is able to take payment should be regarded as being operational.  www.dictionary.com defines the term as, "Fit for proper functioning; ready for use".  I would have to say that as both Arzel personally and matrixwatch.org have stated that they 'know' 29 matrix schemes are operational, it is silly for them now to backstep and try and say that there is no way to 'know' these sites are operational.   

 Would it be of additional help in the History section to include details on Gotmatrix?  This was also a very well-known matrix scheme that is apparently still operational and trading - and is one of the older websites too.  Greg, the owner, is still answering emails - when he chooses!