Is 40% of the Internet custom PHP?

[techlists at phpcoderusa.com]

I have read that 80% of the Internet is powered by PHP.  I've also read 
that 30% of the web is using WordPress.  There is a small percentage 
that are using Drupla, Joomla, Majento... etc.  Lets say that is 10%.

That means about 20% are using other than PHP such as dot.net.... and 
about 40% is custom PHP or web applications.

Your thoughts?