Hi-Lo Indices for 6-Deck S17, DAS, Surr

I have generated the Hi-Lo indices with CV Data, looked at websites and the various books out there, and there is slight variation in the indices. For example, 12 v. 2 can be +4 or +3, depending on the source. Does anyone have or know where to get the most accurate indices for the above game? I know that it won't matter in the long run, but with heat at higher stakes and all the other things going on with what has become an extremely tough game to play, I was trying to avoid the annoyance and have piece of mind that I did the right thing when I have big bets and close calls where it would have gone the other way if I used a slightly different number.