I contend that it wouldn't - extrapolating the figures forwards from 1994 gives an annual 536m journeys for this year, against a projected 1,600m!
BR was forced into the weird conclusion that since it couldn't borrow money (long-term) to invest in expansion*, what it could do was manage the growing demand by raising fares. Big fare hikes equals reduced demand, constant revenue (good) and no need to expand the network (result!).
So, once this fairly odd policy was done away with and BritGov PLC hardened its attitude of making the GBTP pay for the railways (not the ordinary tax-payer) then, oddly, ridership has increased whist the rate of fare rises has reduced (in comparative terms).
* BR was required to show an immediate 8% annual return on investment borrowing, which it could never do. Most of the big capital spend projects of the 70s and 80s were gifts to BR from their buddies at Treasury.