This is self-identification, not the rate at which people are actually diagnosed with gender dysphoria.
Most "transgenders" on the internet these days straight up don't have anything close to actual gender dysphoria. I don't know how many times I've seen people post shit like pic related completely unironically, describing their "gender dysphoria" not as any kind of deep seated discomfort in their own skin, but playing fucking girl characters in video games or the idea of being a fucking anime girl making their peepees hard. Gender dysphoria is a real thing, and consequently transgenderism is a real thing, but these people don't have it. A lot of the "trans" people you see online are perverts living out a sex fantasy, mentally ill, unhinged attention seekers, or some mix of the three.
Hence why we might hit "peak trans", when the fad dies or people admit the emperor isn't wearing any clothes, whichever comes first..