You've probably checked against the "Fusion" list that excludes the EO lines. Post your postcode and we will probably find the missing 41% as EO.
I've looked on the list, it says there's a 13% chance I'm connected to a cabinet which will be getting fibre and a 46% chance I'm connected to a cabinet that won't. I don't know what happened to the other 41%, perhaps that's the probability that I'm not connected to any cabinet?
Or you can download the December raw data and do it yourself . (Remember to search for all occurrences of the postcode, as it isn't in postcode order).