characters: Total number of characters.
syllables: Total number of syllables, as estimated by split length of
'a+[eu]*|e+a*|i+|o+[ui]*|u+|y+[aeiou]*' - 1.
words: Total number of words (raw word count).
unique_words: Number of unique words (binary word count).
clauses: Number of clauses, as marked by commas, colons, semicolons, dashes, or brackets
within sentences.
sentences: Number of sentences, as marked by periods, question marks, exclamation points,
or new line characters.
words_per_clause: Average number of words per clause.
words_per_sentence: Average number of words per sentence.
sixltr: Number of words 6 or more characters long.
characters_per_word: Average number of characters per word
(characters / words).
syllables_per_word: Average number of syllables per word
(syllables / words).
type_token_ratio: Ratio of unique to total words: unique_words / words.
reading_grade: Flesch-Kincaid grade level: .39 * words / sentences +
11.8 * syllables / words - 15.59.
numbers: Number of terms starting with numbers.
punct: Number of terms starting with non-alphanumeric characters.
periods: Number of periods.
commas: Number of commas.
qmarks: Number of question marks.
exclams: Number of exclamation points.
quotes: Number of quotation marks (single and double).
apostrophes: Number of apostrophes, defined as any modified letter apostrophe, or backtick
or single straight or curly quote surrounded by letters.
brackets: Number of bracketing characters (including parentheses, and square,
curly, and angle brackets).
orgmarks: Number of characters used for organization or structuring (including
dashes, foreword slashes, colons, and semicolons).