If you are interested in the actual report you can find in Figure 3 and Figure 4 that clearly show the suicidality and self harm rates of 27 trans people compared to 458 "cis" people. Bear in mind that the recruitment criteria was very strict in that for P1Q Recruits:
"To be included in this phase of the study, individuals had to be 18
years of age or older, identify as LGB or Trans*, have experience from
one of the three mental health issues under study but have been in
recovery from them at least five years prior to enrolment in the study.
In the case of the suicide group, their first suicide attempt was to have
occurred after they were aged from 12 years up to and including age
24. At least six years must have passed since their last serious attempt.
The study specifically prioritised participants whose attempt had been
life threatening whether or not it had been committed with intention
to die."
For the second group ie P2Q the selection criteria was equally strict:
"For this phase of the research we were interested in interviewing
individuals who had experienced traumatic events while growing
up but who did not develop mental health issues later in life (the
‘resilience’ group); as well as those who did not experienced traumatic
events growing up but did develop mental health issues (the ‘risk’
group). For the second group we were also interested in interviewing
individuals who, meeting those criteria, also developed one of the
three key mental health issues of the study: had attempted suicide
while growing up (identifying as LGB or Trans*); had abused alcohol
(identifying as a lesbian, gay or bisexual woman); and had excessive
body image preoccupations (identifying as a gay or bisexual man). "
Anyone with a modicum of intelligence can readily see how using stats from such a study can be "massaged" for the greatest effect of scaremongering. It is worth noting that the stats used by Mermaids come from the larger survey recruits i.e. 2078. The make up of this group was:
"Between June and November 2013, a total of 2,078 valid surveys were
collected. Of all participants, 700 (36.5%) identified as heterosexual,
and 1,320 (63.5%) as LGB+, of which 29.9% were gay, 16.8% lesbians,
16.7% bisexual and 2.8% identified with having an alternative sexual
orientation (e.g. pansexual, asexual, queer)."
I will leave you to draw your own conclusions but here is the actual report from which the figures were derived: eprints.worc.ac.uk/3743/1/RARE-Report-WEB_version_final_20150319.pdf