Is there a location I can download character distributions for frequency analysis used in decryption attempt validation? I am specifically interested in ASCII value [32, 126] frequency distribution for plain English language text. This would imply case-sensitivity and include punctuation. I'm not concerned with data formats.
Second try: Google Ngram Viewer contains raw counts of 1-, 2-, ...-grams of text, retrieved from its book scanning endeavor. The section 1-grams contains counts of the occurence of lettres, numbers and even punctuation. They are provided as tab-separated value files, so the frequencies should be derivable with modest scripting efforts.
Found via Wikipedia article Text corpus.
What about the (frequency analysis) article's first link to Letter frequency (Wikipedia)? It lists letter distribution for English and other languages, all properly sourced:
Letter Relfreq ---------------- e 12.702% t 9.056% a 8.167% o 7.507% i 6.966% n 6.749% s 6.327% ...