It doesn't. It hasn't for some years.
Dinner is no longer a requirement. Being exclusive is no longer the assumed default.
No, I mean the population of the "dating pool." For example, if a "dating pool" consists of 10 men and 1 woman, and the woman enters into a monogamous relationship with one of the men, we can say that "the top 10% of men of this dating pool are dating 100% of the women."
Rappers, actors and people who feel the need to bring 5 or 6 girls on a date, that's so rare that doesn't even merit counting. And also it ends up pretty quick.