I doubt it is anything like as high as 19% in reality.
I reckon a poll that asked questions about specific scenarios would reveal all the "Yes, transwomen are women except for relationship purposes."
I'd like to see a poll specifying whether the TW has a penis or not, "passes" well or not then asking about prison, sport, communal showers, intimate care, lesbianism, choice of work uniform etc.
You see I'd say I'm quite happy to treat TWAW for the purposes of their work uniform (then again I'd ban gender-specific uniforms: men can wear skirts, heels and makeup, women can wear trousers, flats, bareface without discrimination).
I would not treat TWAW for prisons or when considering what defines a lesbian.
I'd love love love to see a proper independent poll on that kind of thing.