The Penn Treebank is composed of professionally-written news text from 1989, when minorities comprised 7.5% of the print journalism workforce; the proportion of women in the journalism workforce was first recorded in 1999, when it was 37% (American Society of Newspaper Editors, 1999).
twitter users in the USA contain an equal proportion of men and women, and a higher proportion of young adults and minorities than in the population as a whole (Smith and Brewer, 2012).