I wouldn't have thought it's as high as 95% as I doubt I'm that much alone in trying to live one train ride away from work.
However you also need to factor in hubs so from the outskirts of Glasgow to Glasgow (1 train), Glasgow to London (2 trains), Underground to another London station (3 trains), train to Paris (4 trains), Metro (5 trains), train to destination (6). Now I don't feel it should be beyond the wit of man in 2016 to have one train do a lot of that and also allow people to board and leave the train en route. In fact iirc correctly one of the drivers for the Channel Tunnel was the Glasgow to Paris idea but it never materialised. To spend billions on a train that gets people from the Ally Pally to Wimbledon just seems very short sighted and unambitious.