whatever that’s meant to mean on its own
Here you go.
https://www.stonewall.org.uk/resources/list-lgbtq-terms
Stonewall uses ‘trans’ as an umbrella term including (but not limited to) transgender, transsexual, genderqueer, genderfluid, non-binary, agender, trans man, trans woman, trans masculine and trans feminine.
They used to include cross dressers, but for some reason they dropped that a couple of years ago.
The most recent census information is not accurate because people were confused by the question, but if you assume that those who wrote in a gender identity different to their sex did understand the question, a third identified as neither male nor female.
A key part of the Hayley Cropper story line was that Hayley passed so well as a woman that the reveal was a surprise. It's clear that UK law was written using the understanding that a trans-sexual like Hayley wished to transition to the opposite sex.
This cannot be assumed of the trans population now. So no, what we understand as 'trans' now didn't exist 20 years ago. (We had more goths though).