There’s no day to day comparison unfortunately.
In 2016, 2.7 million mail-in ballots were returned (3.3 million were ordered).
Total turnout was 9.6 million.
We are already at 3 million ballots ordered. Turnout this year won’t be 9.6 million. I think it will be around 7 to 7.5 million. It might be a little lower even - not sure.
Usual mid-term turnout is 50 to 55% and presidential year turn-out is 75%. 13 million registered voters in Florida. Everyone can figure out what turnout might be based on an educated guess of the percentage turnout they expect.
I have done some work comparing to 2014. I will post more in about an hour, but these numbers are not good at all.