this is very interesting and have been following a discussion which lead back to this post. smartmarket seem to have received transfers of steem and sbd that are not transfers for votes, but funding. I have started to do a little work on this myself and I might be able to make those adjustments for bids sent back.
Also wondering how you got the values for the daily amount transferred to voting services? I have values for this but they are somewhat different to yours. for example on the 15th march the SBD transferred to voting servces (for the accounts listed on https://steembottracker.com/) I have $17444.