This article is in German, so I have only seen the abstract.
Demographic data on trans kids and teens is generally lacking, but there seems to be an increase in diagnoses of gender dysphoria.
“Given the increasing demand for counselling in gender dysphoria in childhood in Germany, there is a definite need for empirical data on characteristics and developmental trajectories of this clinical group.”
This study looked at the patients at one clinic and found that there were significant differences between the girls and boys with gender dysphoria. They suggest that the two groups will need “different awareness and individual treatment approaches.”
Between 2006 and 2010, the Hamburg Gender Identity Clinic saw 45 “gender variant” children and teens. 40 of these patients were diagnosed with gender identity disorder (88.9%).
Differences reported between girls and boys with gender dysphoria:
The girls were older than the boys on average.
A higher percentage of the girls were referred to the clinic at the beginning of adolescence (over 12 years old), although more girls reported an early onset of gender dysphoria.
More of the girls talked about their “(same-sex) sexual orientation during adolescence and wishes for gender confirming medical interventions.”
More of the girls reported self-mutilation in the past or present.
More of the girls reported suicidal thoughts and/or attempts.
The referral rate of girls with gender identity disorder was higher than the rate for boys. They give the ratio 1:1.5. (I am not sure what this means; this is a translation of an abstract.)
“Characteristics of children and adolescents with gender dysphoria referred to the Hamburg Gender Identity Clinic” by Becker I, Gjergji-Lama V, Romer G, Möller B. in Prax Kinderpsychol Kinderpsychiatr. 2014;63(6):486-509.