Which is terrible, because bulimia is more fatal (and just worse on the body in general) than anorexia.
No it's not.
The mortality rate for anorexia is really really high. Partly because starving is really bad for you, but also partly because you have to already be underweight ("significantly low body weight, less than is minimally expected," but isn't specified as a BMI) to be diagnosed with Anorexia Nervosa. If you've just started starving but you're not underweight then you cannot get diagnosed with AN.
The diagnostic criteria were changed when the DSM-IV-TR was updated to the DSM-5 in 2013 (2012 maybe?)
DSM-IV-TR had three possible diagnoses for this stuff: Anorexia Nervosa, Bulimia Nervosa, and Eating Disorder Not Otherwise Specified (EDNOS)
The criteria for AN at that point required being underweight and of female having lost your period for 3 months. A lot of people who had lost a lot of weight and weren't underweight or who were underweight but still menstruating got the participation trophy prize of EDNOS. This category also included people who didn't purge enough to meet the criteria for BN. IIRC most EDs got diagnosed as EDNOS making it a pretty useless catchall diagnosis, and it sucked because insurance was less likely to pay for treatment.
It's also just super invalidating to be told you're too fat to have the real eating disorder.
Anyway, in 2013ish the DSM-5 came out and removed the requirement for amenorrhea for AN and added some more diagnoses. So now there is "Atypical Anorexia Nervosa" which is your participation trophy you're-starving-but-not-underweight-yet specification and "Atypical Bulimia Nervosa" which is your you're-not-B/PIng-enough specification.
These both fall under Otherwise Specified Feeding and Eating Disorders, OSFED. The true miscellaneous category that replaced EDNOS is Unspecified Feeding and Eating Disorder, UFED. They also added or shuffled around a few more named ones that aren't the typical EDs/aren't really relevant here.
TL;DR: in 2010 if you were starving but not underweight you got an EDNOS diagnosis and in 2020 you'd get an OSFED: Atypical Anorexia Nervosa diagnosis, but at no point would you get an AN diagnosis.
So the mortality rate for AN is a mortality rate for a group of people that are all starving themselves and already underweight. It is not surprising that it's pretty fucking high.
I was really active in pro ana stuff in 2010-2011, but back then it was PrettyThin not MPA. I was also somewhat active on MPA for a bit in 2013. I can answer questions about the communities and mindset if anyone's curious.