I am wondering if there has been any research on the statistical frequency of the different parts of speech. I'm looking for something like "20% nouns, 13% verbs, 10% adjectives, 11% prepositions, 5% pronouns, 13% articles, 6% conjunctions, 14% interjections, 8% adverbs".
I am using the word statistical because this would clearly not apply exactly to every passage of text. However, this is just general.