more on menarche and the first coitus

Previous pix are here and here.
Finally, the results with weighted cases. RLMS provides weights as one of the variables.

Menarche:

However the result is the same, median age = 13, i.e., the school's 7th degree. In the 8th degree more than a half of girls are exposed to risk of unwanted pregnancy, since few normal creatures wish a pregnancy at school.

The first sex:

Weighting moves age at the first sex one year greater, 19 rather than 18. But 48.8 per cent of girls starts their sexual life at school. If it starts than it's already late for education, imho.

In other words: the sexuality education must begin at about seventh grade, and instruction in contraception should be a greater part of it.

 

age of sexual debut

These are the RLMS data (round 19, 2010).

Lines belongs to the left vertical axis and represent cumulative number of cases, right vertical axis shows per cents (red/blue).
The age at different personal events is naturally different, median age at menarche is twelve, median age of the sexual debut is seventeen.
Age at which a half of those who had experienced periods, became biologically ready for conception and started their sexual life is nineteen.
These ages are important to consider the beginning of a course of sexuality education: when a school should start it? Imho: fourteen is the latest, or about the seventh grade.

The next important finding is fifteen percent of those who did not start their sexual life by age 35. It is very close to WHO estimates of infertility.