Those graphs are bogus.
The “Exposed thorough hetero contact” numbers should be labeled: “Claimed by patient to be exposed...”
When diligent follow-up is done, men NEVER get it heterosexually, and the women all get it, um, the same way men get it from men.
Honestly, unprotected anal sex from dubious male partners is a terrible risk, and political correctness is silencing that life-saving advice.
Read Michael Fumento’s Myth of Heterosexual AIDS. He told the truth decades ago, and it all came true. He’s also an occasional Freeper, and his book on environmentalism turned me into a conservative.