First, The Transgender Task Force survey says 41% of gender changers will attempt suicide.
"A 2010 survey from the National Center for Transgender Equality and the National Gay and Lesbian Task Force found that 41% of transgender people attempted suicide at one time". http://www.advocate.com/News/Daily_News/2012/02/21/Survey_41_of_Transgender_People_Attempted_Suicide/
Second, The Department of Clinical Neuroscience, Division of Psychiatry, Karolinska Institutet, Stockholm, Sweden, says,
"Persons with transsexualism, after sex reassignment, have considerably higher risks for mortality, suicidal behavior, and psychiatric morbidity than the general population. Our findings suggest that sex reassignment, although alleviating gender dysphoria, may not suffice as treatment for transsexualism, and should inspire improved psychiatric and somatic care after sex reassignment for this patient group." http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0016885
Third, a UK study says,
"There is no conclusive evidence that sex change operations improve the lives of transsexuals, with many people remaining severely distressed and even suicidal after the operation, according to a medical review conducted exclusively for Guardian Weekend.
The review of more than 100 international medical studies of post-operative transsexuals by the University of Birmingham's aggressive research intelligence facility (Arif) found no robust scientific evidence that gender reassignment surgery is clinically effective. http://www.guardian.co.uk/society/2004/jul/30/health.mentalhealth
The objective evidence shows that extreme caution should be used in considering sex change surgery. The Transgender Task Force suggests that discrimination against transgenders is the cause of the high rate of attempted suicide; however, no objective study supports this notion.
Suicide studies show that 90% of attempts are the result of undiagnosed and/or untreated psychiatric and psychological disorders as the real cause of suicide and attempted suicide.
Why then do they claim that only 1% have regret?