In the U.S., the most trans-friendly industry I’ve observed has been at technology companies, though I haven’t seen hard statistics. There is for instance a significant trans contingent at Google, and I have numerous friends who work in tech. One hypothesis about why this is the case is that it’s easier for trans people to have jobs that are not public-facing, because an employer would be less concerned about alienating customers.
In my experience, the fields that seem to be more open-minded about transgender issues are media, journalism, fashion, film, and art. I’ve heard from my transgender friends who work in more corporate settings, such as finance and business, that they’ve encountered some difficulties because of office culture and dynamics that come along with male-dominated fields. In any case, your Human Resources department should ideally be a good resource to help you navigate any anxiety you have about being transgender in the workplace.