The 25-5 was standard with a TH and TT. A special order would be required to ship with a regular hammer and trigger. It would be unusual to find a 25-5 that shipped with a regular hammer and trigger, but a gunsmith could have easily replaced the originals.
At a guess, not that much, maybe 5 - 10%. I know a lot of people that do not like the TT, so I do not think it is a big deal. TS on the other hand, people want those. To me, a hammer is a hammer.