Here is the status of NC's mail-in absentee ballots as of 9-16-16:
Of the outstanding mail-in ballots, 36 percent are from registered Democrats, 35 percent from registered Republicans, and 28 percent from registered unaffiliated voters.
Of the ballots accepted, 45 percent are from Democrats, 31 percent from Republicans, and 24 percent from unaffiliated voters.
In comparison to 2012's same day of mail-in absentee ballots:
Democrats are 214 percent of their comparable 2012 same-day numbers, Republicans are 153* percent of their comparable 2012 same-day numbers, and unaffiliated voters are 288* percent of their comparable 2012 same-day numbers.
There seems to be a quickening of mail-in ballots from North Carolina voters. It's still early (today will be a week of accepting ballots), but the trends, if they hold, may seem to indicate a real interest in this year's election, by the three registered voter blocks.
*Update: corrected a typo of the percentages for GOP and unaffiliated.