<p>I don't know of any document frequency lists for large corpora such as the web, but there are some term frequency lists available. For example, there are the <a href="http://wacky.sslmit.unibo.it/doku.php?id=frequency_lists" rel="nofollow">frequency lists from the web corpora compiled by the Web-As-Corpus Kool Yinitiative</a>, which include the 2-billion ukWaC English web corpus. Alternatively, there are the <a href="http://storage.googleapis.com/books/ngrams/books/datasetsv2.html" rel="nofollow">n-grams from the Google Books Corpus</a>. </p>

<p>It <a href="http://arxiv.org/abs/0807.3755" rel="nofollow">has been shown</a> that such term frequency counts can be used to reliably approximate document frequency counts. </p>
Resource that provides number of documents where the term is covered
<p>I am looking for resources that provides the number of documents a term is covered in. For example, there is about 25 billion documents that contains the term "the" in the indexed internet.</p>