I am looking for statistics regarding vote by mail. I am primarily interested in the recent US presidential election of 2016, and I know not all results are in yet, but I am also looking for the same statistics for the 2004, 2008 and 2012 elections. So far, I have found next to nothing. So precisely I am looking for:
1) The results of the vote by mail (number of votes for each candidates) by states, and if possible, by counties.
Are the states required to publish those results, or are the vote-by-mail just counted together with the other votes of the counties where the voter is registered? Ideally, a site containing the results of vote-by-mail for all states would be perfect, but if the data has to be extracted on the site of each state, I would be willing to do the clerical work to copy the numbers into a spreadsheet. Simply, even on site states, I am not sure where to find these datas, nor if I really should expect these data to be available.
2) Data on voters-by-mail: registration, age, income level, race and ethnicity, gender, etc. This I suppose will come from pollsters rather than from the states but I would be thankful for any link containing this kind of information.