That seems like kind of a strange statement. If you take it literally (and how else could you take it), it means either that 100% of babies born in Europe were conceived by artificial means, or that there are no children born in Europe at all.
Well, perhaps he didn't mean it.
American Heritage Dictionary
sex·u·al·i·ty (...) n. 1. The condition of being characterized and distinguished by sex. 2. Concern with or interest in sexual activity. 3. Sexual character or potency.
sex (...) n. 1.a. The property or quality by which organisms are classified as female or male on the basis of their reproductive organs and functions. b. Either of the two divisions, designated female and male, of this classification. 2. Females or males considered as a group. 3. The condition or character of being female or male; the physiological, functional, and psychological differences that distinguish the female and the male. See Usage Note at gender. 4. The sexual urge or instinct as it manifests itself in behavior. 5. Sexual intercourse. 6. The genitalia. --attributive. 1. Often used to modify another noun: sex education; sex crimes. --sex tr.v. sexed, sex·ing, sex·es. 1. To determine the sex of (an organism, especially a hatching chicken). 2. Slang. a. To arouse sexually. Often used with up. b. To increase the appeal or attractiveness of. Often used with up. [Middle English, from Latin sexus.]
I am giving the news agencies the benefit of the doubt in assuming that they translated Mr. Djerassi's comments correctly into English from Germain (out of "the Austrian newspaper Der Standard). I am further assuming that the news agencies intended sense #2 of "sexuality" and neither sense 4. or 5. of "sex" as given by the American Heritage Dictionary.
From the rest of the cited Catholic News Agency article:
According to the Guardian, Archbishop of Vienna Cardinal Christoph Schonborn told Austrian TV that Pope Paul VI had predicted the pill would cause a dramatic fall in the birth rate.
“Somebody above suspicion like Carl Djerassi ... is saying that each family has to produce three children to maintain population levels, but we’re far away from that,” the cardinal said.
Perhaps we should also nit pick that alleged statement of Cardinal Schonborn (I believe one of the main if not the main author of CCC) since the correct number is 2.1 and not 3.0 ? Of course, it is rather hard for a couple to have 2.1 children.
I admit that I have not read Humanae Vitae. If you want to nit pick something more challenging, though, I'd suggest that you take on Humanae Vitae [sp?] as a challenge.